in this short video i'll be taking you through how to approach any paper thoughts and to the coursework questions from the cambridge igcc geography paper that looks at river investigations now i could have gone through past questions but really when you look at past questions and you put them together and you look at common questions that appear and you look at the mark schemes really this video is to draw out the common language and useful points and to help you approach each type of questions there's all this also is a really good video to help you with useful language and points to consider if you're writing coursework i as i go through how the method how you can use the method to collect data and common issues associated with them how you can improve their reliability but really with this video um it's impossible to cover every aspect every every question asked in this um paper is slightly different than the previous topic if it's like on coast one year it'll be a slightly different focus on coastman previous year so really this is just general points so it's up to you to practice practice practice to use this guidance in the videos to help you really you need to go through previous questions so this video is split into several different chapters each chapter looking at um each part of the uh coursework mark schemes the introduction data collection data presentation data analysis evaluation conclusion now remember you won't get an even split between those each of those is worth 12 marks you won't get an even split between those and every single paper some exam papers focus maybe on data presentation or data collection or you exploring the hypothesis whether or not you've proved or disproved this so that's why i've structured it in this way so when you are using past papers you can look at the chapters and you can go back and review the various uh points to help you explore this now i will say with paper forward since the coursework really the introduction uh draws on uh knowledge and skills learnt from paper one and two as long as you revise really well for people one and two the introduction questions shouldn't be too difficult data presentation is really straightforward as that tends to be looking at um completing graphs data analysis is you looking at the data deciding if you proved or disproved but really data collection and evaluation are the ones that uh is probably the knowledge that's specific to this paper you have to know how to collect certain data so for example in the case of rivers how do you carry about how you look at velocity in the river the width and depth water pollution and you also need to be aware of common reliability issues so that's what this video is looking at so really that's why i split in data collection into the various methods and i've tried to find questions that get you to think about um how you can sort of look at the reliability of these methods now like i said i've looked at every paper going back to 2016 so i might have missed something else so this this video really gives you an overview of each of those methods again it requires you to practice now i'm not just doing this realism doing this for a whole host of other videos if you do like that please do like do subscribe if you think it'll be useful for you so introduction style questions so hypotheses as you know with this paper it's all about a student has come up with two hypotheses and you will have questions about those these are the most common ones that occur within rivers you can see here i'll provide you a selection of some of the hypotheses that have occurred in various past papers and so use your hypothesis for a rhythm i guess investigation will do one of the following state how something will change along the river or over time so something like velocity or pollution levels will increase or decrease with distance downstream or would increase or decrease between um this year and the next year you might also look at ask you to compare two factors to find the relationship so as one increases what should the other do so if the velocity of the river increases what should the what could the width of the revert do you might also compare two factors to see which one is greater an example for the infiltration rates so the infiltration rate of penetration is greater on the steeper sloping lands and so when you do construct a hypothesis you expect it to be true if they are false it is the opposite so for example there is no relationship this fact feature hasn't increased with distance downstream and so stating how something would change along the road is probably the most common hypothesis that will be used in this exam most of those uh most of that those um the hypothesis is based on what we call the bradshaw model the actual model shows how certain characteristics of the river will change as the river flows from its source to its mouth now these particular characteristics should increase from the source to the mouth they are the width and depth of the river as more water is added through tributaries and things like that then there should be greater erosion taking place because the river has more energy therefore the width depth increases therefore the cross-sectional area of the river should also increase the velocity as more water is added and there's greater erosion the channel becomes smoother friction slows down the velocity of the river should increase and if so if the cross-section increases and you times that with velocity then therefore you've got the discharge the amount of water flowing through a particular point so all of these should increase with distance downstream and of course the wetted perimeter the following should decrease with distance downstream sediment size with more water it's more erosion sediment becomes smaller sediment shape more water more erosion sediment becomes rounder and smoother the gradients as there's more vertical erosion and eventually the river will flatten out therefore the gradient will decrease and so these are the types of questions that you could ask that require you to have knowledge of the key terms and theories associated with river investigations so for example here simple definitions and then again linking a key term of this particular part in a river begins at its source here looking at how the various characteristics should increase or decrease with distance downstream and so again here you can see i put the mark schemes in to show the various bits and bobs that you should include as well um there are some nice questions here this is for three marks describe possible changes in the features of the ribbon it's valid downstream um i've always found this table to be quite helpful uh so the actual model these are the characteristics of the river that should increase these the ones that should decrease in terms of other features of the river landforms these are how um the landforms that should that tend to appear or start to appear at the various courses of the river and this is what the valley and channel should be doing and processes that occur so i think this table is really useful when looking at the river characteristics and you can link this to case studies of paper one on paper t and so because you've got so many different characteristics and if you think about it it's actually really easy to write an answer to this so here the real challenge will get wider and deeper a distance downstream and start to meander the river will be at its steepest in the upper course of the river and look at all those various points that you can include for three marks again it requires you to think about why uh um sediment that should come around her or why the discharge should change and so again here i've put some various comments here based on the mark scheme for you so again look at your notes include them into your revision look back at paper one paper two and have a clear understanding of why river characteristics change your distance downstream other questions that do appear um you've got things like water pollution that you might not necessarily need to be aware of in depth for paper one paper too but you are expected to know it for this so again here think about what could cause pollution fertilizers from farm could run off into the river industrial waste from factories so think about it that if you're unsure and again i'll give you some points here why would tourists uh affect infiltration rates what infiltrations about water going into the soil loads of taurus they could flatten the soil harden it make it more impermeable so again here's some various points like that so there's anything you're unsure about that you might not have studied with paperwork on paper too in huge amounts of detail think about it apply it to other situations data collection questions like i said at the start these questions are perhaps the ones that are specific to the alternative to question paper and these the ones that often are the most technical in terms of the language you need to know and perhaps the hardest to learn because there are for some methods very specific equipment that you need to use and you have to carry them out in particular orders so this video please do use the chapters to go through each particular method if you are revising and you want to know how to approach that if you are using this for writing your course but again the language in the master scheme might be really useful to help you write in a very concise and focused way so i've broken down to these various points we're going to be looking at sampling types of data why we do a pilot study common risks associated with investigation and various methods that you need to describe so again use the chapters to wind forward or back accordingly and so again types of data really for investigations there are two types you've got primary and secondary primaries anything that you go out and collect secondary as data has been collected by somebody else and so you need to be aware of the strengths and weaknesses of each one so again i've tried to summarize this for you in a table so again pause the video make some notes or add this these points to your notes um now when it comes to a river sampling is really important it is impossible for you to rivers can be thousands of kilometers long hundreds of kilometers long it is impossible for you as a student to actually go about and look at every single point on the river that's why we do sampling sampling is ensuring that you have enough sites to allow you to make a conclusion you can have too few you can also have too many of them which makes it impossible to do so you need to get a balance right and that's when sampling techniques come into play so these are things we need to consider for river so systematic sampling this is where observations taken at regular intervals eg we ask the fifth person or we carry out an investigation every kilometer so for example here i'm asking the fifth person nice and straightforward random sampling on the other hand is when you as every point has an equal chance of being selected so there's no fixed amounts you just ask whoever or you just choose random locations to do the investigation we'll stratify something where we sort of group data we look at key aspects of the river so for example upper middle and lower and then we choose a number of sites within each one you can combine so we've got stratified random sampling where we group people and then we randomly select or we have stratified systematic sampling where we sort of uh we okay group of people and then we choose the third person from each group so some things to consider about sampling techniques when it comes to river investigations obviously the larger the sample size is the more accurate representation of the whole but sample size do need to take into account the time so are you doing it over a week or a day how much do you feel like you can actually do this do you have the amount of resources behind you to enable you to do this big enough group and also you need to avoid buyers if you focus on one part of the river that's obviously not reflective of the whole river so again you need to consider this so how do you go about selecting a representative sample for a river if we were to use random really it wouldn't work because you might miss out on a huge part of the river and also you would have accessibility issues safety issues you could randomly select those sites and they might actually be really dangerous to go to and again the river might be massive and you randomly you might only select a small part of that river yet there might be huge changes along the course of the river so perhaps random might not be a great shout we could also do stratified sampling so like i said the river is divided up into the upper middle lower course so here we go and then we can select site from each one there we go now in reality this might not work there might be too few sites three it's not enough for a long river again are those sites accessible is it safe to get there does it take into account the length of the river and the depth of the awards for those particular sites so again these are the factors that we need to consider when using stratified we could do systematic sampling so nine states nine sites sorry every one kilometer here we go but again same similar points as before in reality this might not work due to the accessibility of those sites are they dangerous to work in does that take into account the whole length of the river so if you were going to do a roof investigation you might sort of do something like stratified systematic sampling so you've got three sites every one kilometer within those particular courses the river but again when you're selecting your science you do need to be aware of are those sites easily accessible and safe to work in and does the are they representative of the length of the river so yes you might not be able to select a site every one kilometer but you would try to as much as possible yet in your evaluation you recognize that you weren't able to do one every kilometer because of the issues involved at those sites too dangerous water too deep etc so so many questions that might be asked in terms of this um this is kind of tied in a little bit of risk assessment so i'm going to be repeating myself a little bit it's just three factors the students should consider in choosing their fieldwork sites so again safe the weather conditions before enduring hazards human influences all these various factors like that okay and i've sort of summarized them nicely into this this question to summarize the key things to consider in the masking to do include include these into your notes so another aspect of before you go about doing investigation is identifying the risks now you as students might not play a huge part in this this is mainly down to your teachers the people organizing the trip but you do need to be aware of risks and how you can manage them in this paper and when you go about collecting the data so these are some of the common ones that are associated with um rivers is it too hot too cold bear in mind the river changes if you're going towards the mouth of the river is the river tidal like the thames could you slip if you drunk the water or you fall in accidentally consume some of the water could you get ill the time of day would you do this at night or during or during the day could you get lost and is it safe to access these all the various things that you could do and actually a lot of this is common sense so let's look at some common risk assessment questions first of all completely by suggesting different ways to reduce three possible risks you see the possible risks how do you go about reducing the risk of slipping perhaps you wear sensible shoes get disease or illness from the river water uh avoid drinking the water falling into the river and getting injured you might again wear sensible shoes check the depth of the water things like that mark scheme okay work in groups avoid slippery or steep slopes things like that so nice common points here again you can see there's some common parallels between different exam papers um particular cautions to protect students and things like that so insects or animals in the river protection such as gloves long sleeve long trousers insect repellent so again a lot of this is common sense other questions that are associated with data collection is why do we go about doing a pilot study now pilot study is an investigation that's carried out before you do the main data collections so why would you do that really they asked you do this to answer several questions can a full scale study take place you know are all the sites safe and accessible do you require additional costs and resources as well it helps people to familiarize themselves with the for the method so when they're out and about they know exactly what they need to do they can so it makes it the more efficient on the day of data collection so here are some questions for you to consider um explain what a pilot study is and give one reason for doing a pilot study so again here this little definition and these are the various reasons why people do it so again include these into your notes please some other examples identify two advantages doing a pilot study so again learn how to use the equipment and practice fieldwork techniques here they are so please do pause this video rewind add these reasons into why we do a pilot study and it's not just for rivers pretty much you can apply this to any investigation that could be asked in this paper so data collection methods this is a section split into really two parts describe how you collect data for i'm going to describe how you collect data for the different investigations and with the required equipment and then i'm going to look at the various strengths and weaknesses associated with each method and how we can go about making it more reliable um the way i've done this i've split this up into many chapters so you can look at each individual method i've looked at various past questions and i've pulled out common um phrases that are associated with the mark scheme so if you are struggling you can also use this common phrases and you should get at least one or two marks but also it shows you how you can apply this this video to loads of different past questions and ask you about how we can collect data for these methods so the methods that you need to know for rivers if you're looking at how a river changes the distance downstream drawing heavily on a branch of model you need to be able to tell the examiner how you can carry out the width from depth and with that cross sectional area the velocity and with that the discharge the wetted perimeter sediment size and shape and the gradient now with other methods you might be expected to know water pollution calculate oxygen levels infiltration rates and so it's really hard for me to go through um each method because there's only been for example water pollution and oxygen levels one exam question so i've used that heavily typically if you're unaware if you've never studied it and they might they'll give you a lot of help there might be a figure that tells you how to go about doing it and so you have to apply that knowledge but we'll go through it now so equipment needed for river investigation here we go got some ranging poles tape measure a ruler flow meter floating objects can align sir clipboard pen and recording sheets quadrants stopwatch and calipers other common equipment requires a biotic index for water pollution [Music] power scale of roundness and this is the diagram i pulled out from investigation looking at how we measure invest infiltration rates so these are all the various things that you need to be aware of so what the equipment used for just to summarize ranging poles marking out the size and distances tape measures for working out distances etcetera etcetera so please do pause this video read through it just to be aware of what they do i will go through them a lot more when we go through the video i'll just go through each individual method so please if you know how to do one just recap make sure your notes are required you got your the mark scheme you can be incorporated into your notes if not please do get a past paper house in front of you and have a go yourself or some diagrams have a go at trying to answer a question and then use the mark scheme to use the video to help you ensure that it is the perfect answer so just to outline what a describing a method question is question usually is four marks five marks if you need to write a hypothesis for these questions you have to include the equipment that you would use and describe how you or a group of students will collect the data you could also be asked to draw a diagram so it's important that in your revision notes you can draw that diagram structure now uh these one might tell you is mainly for actual models and the any points highlighting orange usually is something that you could write that typically will give you a mark so generally speaking this is the structure that you should use when answering questions might primarily associated with how something will change with distance downstream choose at least 10 sites along the river and then you would go on about outlining how you collect the data with the various equipments but also if you repeat three times each site to get an average and you write down the results and recording sheets and repeat nine other sites downstream to see if there is a change really if you write one of those three uh points highlighted in gold or orange on your screens and actually that is enough typically to give you a mark as you'll see as we move through so this is a common question that came up this is a very nice question that came up in 2021 um sorry i feel the method test this hypothesis you write a hypothesis and you talk about a fieldwork method this question refers to how you could refer to the width and depth of the river the velocity sediment around this but you could also look at other factors as well like gradient and things like that so width and depth to work out width and depth you would need the following equipment some ranging poles tape measure ruler and clipboard pen and recording sheet so here we go this back to the question what hypothesis could you write for width or depth resistance downstream increases the depth will increase and likewise this distance downstream increases the width will increase so how do we go about writing this um how do we get full marks this question for the filbit method so again back to the structure we'll show you how something will change this inside stream i'm going to write about how i should choose at least 10 sites then before talking about how to cut data then repeat three times write down the results and recording sheet and repeat at nine other sites so how do i write my answer using that structure i talked about firstly choose at least 10 sites along the river second each site two ranging poles are placed on both sides of the river directly across from each other and kept in a vertical position thirdly place the measuring tape between the ranging poles to measure the distance it must be kept taught repeat three times each side to get an average write down these results in recording sheet repeat at nine other sites downstream to see if there is a change so there's my answer for four marks if you look at the mark scheme choose at least two sites along the river yep done one student poll on each side of the bank yep done place measuring tape kept torts one mark directly across from each other so you can see here my answer is very detailed but i've got everything that i need to get four marks if not more now if i was writing this in a piece of coursework or i had to draw a diagram and this diagram i've got from the field of studies council i would do something like this so if you're doing this for coursework you need to it's actually a great way to say word counts if you can provide an annotated diagram of how you collect the data so again you might want to use something like this and you might want to try and write it a bit more concise just to help you summarize everything and to make it clearer and keep your word count down so again if you would like to use this and see how it works in a diagram pause the video so a method to measure channel depth firstly choose at least 10 sites along the river secondly each site two ranging poles are placed on both sides of the river directly across from each other it kept the vertical position and as you can see here again i've kind of include it's very similar to width but obviously now i'm measuring the depth so if i go back to the mark scheme you can see i'm again i am ticking all of the boxes required for this mask and again you can see recording the results um repeats at a second site downstream and calculate the average are very common things to include for river investigation and again this is what the type diagram i would look like if i was drawing it for my coursework or if i had to draw a diagram so again thank you phil cities council again you can see here just to prove that the market schemes are very similar two questions from two different papers if you look again i've included them uh questions here and if i look at the mark schemes again i am my answers refer to this is for width and depth so i've combined them but if you look at the mark scheme again very similar points between different years that need to be included so please these answers shown in the video should be enough if you can remember what you need to write to get you the marks okay cross-sectional area um we said it's when you have to times the width of the river excuse me by the average depth so again here the width through is 2.4 the average depth is 0.27 then i've got that by doing that times two together 6.48 and again the mark scheme is there so the width of perimeter what is that well it's the entire length of the bed and the rear bank size in contact with water so it's not a straight line it is the entire river bed to do that you lay a chain or tape measure along the rear bed from one ranging pole to another and the wetted perimeter should be much longer than the channel width again i took this picture from past paper and again uh typically you might not be asked to describe the methods but if you did you got the previous video um very similar to width but instead of doing a straight line you just try and lay the measuring tape flat along the riverbeds but you might be asked from a couple of difficulties or things like that so again here um you've got the mark scheme to help you now for the next method that you have to be aware of is when you are measuring the velocity of the river and there are two methods that you might be asked to describe or you might have to suggest why um the flow meter is more accurate than using a floating object so the equipment that you need for measuring velocity is ranging poles some tape measure flow meter or floating objects clipboard pen recording sheets and just stopwatch so these are the type of questions that you might be asked describe a film method to test this hypothesis or describe two methods that students use to measure velocity so that's seven marks you've got there on the right hand side for knowing about the various methods so how would you approach it well if you're using a float you would have some sort of diagram that looks like this you would choose at least 10 sites along the river and secondly you would place two ranging poles 10 meters apart using tape measure one upstream and one downstream and making sure they are in line with each other so you can see that in the diagram next you would place a floating object and the floating object would be released using a stopwatch the students will recall the time it takes to go between the two ranging poles and then the velocity is calculated by dividing the distance 10 meters by the time it took to give you um meters per second you would also repeat this three times at each side to get an average and then close to the left bank and then the right hand bank again multiplying that by three and so the overall average is written down on the recording sheet and then euro repeats and nine of the sites downstream to see if there is a change so that's how you would record velocity using a float two ranging poles ten meters apart time uh record the time it takes for a float to go between the two poles so if i was to show you my answer here you can look at the two mark schemes i've got for you and you can see that if you read the mark schemes from the two questions i showed you at the start and actually our answer incorporates the best elements from each one and so we have a nice answer that will easily get us four marks if not more okay the second method that we use and perhaps the more accurate one is a flow meter you can see the flow meter there is propeller that you place within the water and then you and then you've got a digital display that tells you the velocity at that particular point so again like using a floating object you would choose at least 10 sites along the river at each site you would place the flow meter into the center of the river with the propeller facing upstream and making sure there are no obstacles in front of that propeller and then after a minute you would write down the velocities shown on the display or you might get given a graph that you have to sort of do a calculation for you repeat at different points across the channel and calculate the average and write that average down on the recording sheet and then you repeat it very a variety of other sites downstream to see if there is a change so unlike the floating object this one is exactly the same you have left hand bank center right hand bank and you would be measuring the velocity using the propeller with the pellet facing upstream at those particular points so nice and straight forward again here we've asked the placement answer we look at the marker scheme on the left-hand side and you can see again very similar points that need to be made at each each um from each mark scheme so i might answer again incorporate the best of those mark schemes so you should have an answer that depending on what the question asks will always get you the maximum marks so again i'm noticing a question where you're asked to explain how you calculate discharge um describe the methods that you would go about with the discharge but remember it's basically the cross section area width and depth width times average depth plus the velocity if you had to do that you'd have to describe each of those three methods of collecting those data but you might be given a formula here so you can see the first part of this question is asking you to show you the formula to work out the cross-sectional area so you can see here that you need to times the width and the average depth so with the ruler 3.45 average depth of 0.31 meters times these two together you get 1.07 meters squared so if you check the mark scheme there we go now if you move on to the second part of this question it explains how you would go about calculating the discharge so they say here the the discharge is calculated by the formula average velocity times cross-sectional area and they've already done that for us and they've given us some data now i'm going to go into how to answer this question in a bit more detail in the data analysis past this video but i'll just quickly recap for you now what is the correct conclusion to hypothesis one well hypothesis one is true the discharge has increased with distance downstream at site one is lower than the discharge at site three and i've quoted some numbers for you there and then you have to give one reason why river discharge changes downstream well if the volume of water is increasing with distance downstream any particular point and how fast that is traveling therefore there must be more trippy trees have been added to the river increasing the amount of water check the mast scheme there we go another method that you're expected to know is how to calculate the gradient of the river for that you need some ranging poles tape measure obviously clipboard recording sheets and a clinometer these are some of the questions that they ask again four marks describe how you would use the equipment shown in figure 2.3 here we go to measure the angle of the slope or describe how the students measure the angle of the slope of the river beds so remember back to this these are the golden things you need to include for a rhythm investigation so how would you write on the answer so here's a diagram i've got it for you i've put this on here just in case you want to use it for a piece of coursework i'll choose at least 10 sites along the river in the center of the river i would place two ranging poles 10 meters apart one upstream one downstream in line with each other one of the students would hold the kilometer next to the pole that is downstream and point at the same point on the pole that is upstream and then the student would record that angle i repeat this three times at each side to get an average maybe on the left hand bank center and right hand bank and then i write down each result on my recording sheet taking an average and then i'll repeat this at nine other sites downstream to see if there is a change so very straightforward two ranging poles 10 meters apart one upstream one downstream in line with each other the students chooses a point on the one that is downstream the kilometer looks up to the same point in the ranging poles that is upstream releases the trigger of the kilometer and records the angle again if i was to show you the mark schemes and here's my answer you can see again really important that you need to have the equipments and then you outline clearly how you place that equipment in the river and how you use it to ensure that every single time you are reliably collecting the um the angle of that slope or of the river channel so let's move on to the next one settlement size and shape for this ranging poles tape measure clipboard pen recording sheet calipers and a scale of roundness so how will i collect this data well here's my diagram to show you again very similar to average depth i choose 10 sites place my ranging poles and then i would decide on the sampling technique and i could within that river between the ranging poles randomly pick up between 10 to 20 pebbles or i could as i measured the depth i could pick up a pebble every tenth interval of that width it's entirely up to you and then once i've got that pebble i would then compare it against a scale of roundness to see how the um identify the shape and that would write that down in my data collection sheet or to measure the length i would use calipers and i would measure the longest part of that pebble i write down all my results on the recording sheet to calculate the average and then i'll repeat this at nine other sites to see if there is a change or distance downstream and here we go if i compare it against the mark scheme here from that question before you can see that again it's all about how you would go about me using the sampling techniques are really important here how you go about that this is the one that you need to mention particularly set in the size and shape but it's all about how you would go about recording that data ensuring you've got the same measurements of roundness and length and then recording those sheets and calculating an average so in terms of measuring infiltration i've only seen this question appear once since 2016. you can see a diagram of how you measure infiltration here and you've got the question outlined before you now sometimes when it comes to these papers of a very unique method or a very or a method that is rarely asked or it's unlikely that you've done it might give you a little bit more information so the second part of this question outlines exactly the length of time that you took so it's really important that you read the whole paper first so if you look at that it says the um the students recorded the water level on the plastic tube every minute for 10 minutes so that's information that you can include in the first part of this answer so again if i've got my golden rules and i look at the mark scheme you can see here that i need to choose at least 10 sites that go away from the lake up hill because that's what the hypothesis is exploring at each site i would insert the plastic tube into the ground that you can see in the figure so it is in a fixed place i pour water into the tube until it is 120 meters it's so millimeters that you can see there and using the stopwatch time a minute and then measure the water level in the tube do this for 10 minutes or until the water is infiltrated into the ground so every minute you are recording the level of that tube i repeat again in each site and i record my results on a recording sheet and this is the mark scheme so again pause the video look at what you have to write include that into your notes now the question moves on and shows how you calculate the infiltration rate the time it takes to how fast water is infiltrating into the grounds you've got the falling water level divided by time and that gives you the answers you need to work out what that means to show the calculations so again you've got the figure here and we need to do this for site two so you've got what it was naught minutes and then you got what it was at ten minutes and for that you need to work out the difference so you've got 120 minus 48 which in this case is 72 and then 72 divided by 10 minutes what you're telling me is every minute how much water is infiltrating into the ground so that is 7.2 millimeters again um water at the start water at the end what difference is divided by the time you measured infiltration rate for known method again i've only seen this once it's water pollution and so here i've outlined the method that you would use based on the mark scheme and based on the um information that was given to us in the figure because unfortunately when i downloaded this from the cambridge website some information was missing about the method so i had to use a different paper quality wasn't great so here i just outlined that method for you so pause and add to your notes and these are some other questions that they asked us to look at again you had a biotic index and you had to do some basic questions there the first one was really easy which biotic group contains the cell bug so again you have to find it and it's four here explains you how to go about collecting um calculating the bisect index score so you can see here takes you through an example and then here you just have to times the two together so three by four four times three so on and so on and so on let's give the answer 27 27 divided by nine please do have to find this where it is on paper online download it have a go through it because it is quite is very rare that you could be asked this but just in case you can see it there and um just review at your own time to give you the three and if we check our answers here you can see we are all correct quite a lot of work to do for four marks but again very standard for marks if you review carefully review the method go through it logically and you should be fine moving on to evaluation style questions this is questions that really ask you to think about the reliability of the methods that you have used to collect data not every exam paper asks about the reliability for every single method so again i've had to use the ones that i've i just show you the ones that i've found questions for but please do think about it a lot of it is common sense so when looking about the reliability or identifying weaknesses and difficulties you're thinking about have i collected enough data was it the right method did weather conditions influence what i did was there any human error involved in collecting this data were there obstacles in the river that might have affected me were there human changes or physical changes to the river that might have influenced the data so for example was there a waterfall in the way was there a landslide did humans build a bottling plant for these type of things so here are some questions for example um you can use this method here for velocity explain why students may have reduced some reliable results so could weather conditions influence this no human error possibly did you every single time pick up the float as soon as it crossed the finish line were there obstacles in the river that might have affected the floats so again some points here float gets stuck and obstacles along the way human error that ensuring that the start and stop time is fair again i'm asking it gives you some extra points there and then we look at the um other questions about measuring the uh the width of the river um you want to make it more reliable you would obviously take an average you make sure that the tape is taut every single time um sorry between ways the measurements were reliable again some other points here for oxygen level but how you consume something like an oxygen digital meter for a flow meter or pollution levels is exactly the same every single time so general points is the data easy to collect were people working in groups were there sites selected within an area or along a transect was it on the same day was the average calculated there's a method selected enabled change to be shown was biased minimized was the equipment working these are all various points that you could use to help you with suggest improvements or understand the reliability of the um of the methods and again think about would a digital display solve the issue so if you're looking at a float or a flow meter one of the differences between the two methods are the fact that it's a digital split there is no human error involved in reason that you just have to write the numbers shown as i said here um how you can improve the methods so again if you wanted to improve the right bit of velocity and gradient measurements here are some ideas a pilot study is a really good one you take more measurements calculate an average you use a flow meter so these are various things that you can consider again pause the video look at generic points that you could incorporate into your into your master for example a pilot study is one way that you can improve you can calculate an average you can do that for any method that you use so again um really nice or you could repeat the investigation on different days month season to compare results those points there are really good generic points that you can apply to any investigation so again just to recap points to improve the reliability take measurements and average repeat at different times months or years and compare work in groups collect more data and increase the number of sites is there an alternative way that you could use is there a digital alternative and so these are the things that you need to consider when improving the reliability of your results today's presentation questions remember there are a huge range of techniques they could use now i've made another video that talks you through uh the various different uh data presentation techniques that i've found that have applied to any past paper so if you look at that video if you're unsure how to do a pie chart or a bar graph or a flow lines or iso lines have a look at that video it takes you through it it might not necessarily be on rivers it could be on any um other investigation but it's the technique of drawing those graphs that's really important that you can apply here so please do look at that video if you are unsure when it comes to answering past questions um you can see the link in the video or in the chat or please do just explore my channel but i'm going to take you through a range to show you what you need to do and really just re-emphasize this is down to practice practice practice so some techniques you could do simple bar graphs scatter graphs pie charts cross-sectional graphs again scatter graphs and applying showing various measurements um again a line graph to show gradients there is so much variation within these questions that's really hard for me to show you in this particular video this video will be too long hence the other one but do not miss these questions as you look at past questions you can see they sneakily include these questions into the exam paper so make sure you do not use them whenever you're drawing your graph look at the how the examples around where you need to draw have been shown and copy exactly what they've done or go about thinking about how they've calculated that and drawn it before you draw yours use a pencil so you can always rub it out if you make a mistake make a mistake and do practice by looking at a whole range of past papers not just for rivers but in any topic to get that practice of drawing graphs understanding how they might use a slightly different technique each time so you just are used to when you see this question you know that in this paper i should get 12 marks at 60 for completing graphs so another chapter is when we look at data analysis so you look at you've shown the data the database is presented to you and you need to decide whether or not your hypothesis has been proven or disproved true false or partially true so again i've looked at this question again very simply you've got the data you need to show if it's proven so here as i've said to you before that hypothesis one is true real discharge does increase your distance down the stream this is showing because of site one it was 0.2 qmx and it increased to 0.48 qmx at size 3. so this you can essentially this two marked answer sums up exactly what you need to do for these questions that are typically four marks you state if the data collected is proven hypothesis and you provide evidence to show that as this mark scheme for two months clearly shows so again here's some questions here for you a whole variety of data again you'll see this as you go through exam papers and past papers but there is a certain way you answer these questions you must first of all read the question carefully and just clearly have in your head what is the hypothesis trying to prove does the question actually state for you if it's true or false if it doesn't look at the data does the data prove that the hypothesis is true partially true or false and if it does that's the first thing you write any question unless it's been stated for you that this hypothesis one is true hypothesis two is partially true that is the first scene that you write and then because generally nine times out of ten this is always one mark and then you find and write evidence to support your view do go and practice these questions using that structure if you look at the mark schemes again for these questions you can see one mark certainly for stating if it's true or false and then you get marks for showing that in evidence so now it's over to you go online find past questions for paper four this video really was general guidance for river investigations every past paper is slightly different even if it's on the river so do as you're answering questions on rivers review this video go use the chapters to wine forward or back to the various sections just to help you clear your mind if not look at your theory from paper one paper to practice does make perfect with this question using the mark scheme incorporate the mark schemes into your notes i hope i've shown you i've given you marked schemes that enable you to write a very good answer for every single data collection method which is pretty much the perhaps the most unique information that you need for this particular exam paper and do watch the other videos to find out more about the different investigations in more detail to help you approach this question and if you really like this video please do subscribe and share it um it just helps me know that exactly what i'm producing is helpful and obviously i can upload mend and change my videos if you feel they need to be improved or i can respond to your comments for this video thank you ever so much