hello this is Dr Grande welcome to my video on calculating and interpreting Ada and Ada squared using SPSS Ada is a measure of Association that we use when we have a nominal variable and a variable measured at the scale level so taking a look at these fictitious data I have loaded in the data editor in SPSS I have a variable named treatment and this is an independent variable with three levels individual group and treatment as usual so this would be Individual Counseling group counseling and the counseling treatment that was provided as part of what the agency would normally do and you can see moving to the coding behind it is coded as 0 1 and two so independent variable with three levels then I have a dependent variable here named depression that has scores recorded as continuous and let's just presume that these values are recorded as t-scores a tcore is a standard score with a mean of 50 and a standard deviation of 10 so to calculate the adative value for these two variables we go to analyze descriptive statistics cross tabs I'm going to move the variable that we're going to treat as the independent variable into the row list box and the variable that we'll treat as the dependent variable into the column list box over here to the right the top right I'm going to click statistics this opens up the cross tabs statistics dialogue and you can see under nominal by interval there's only one option here and it's Ada so I'm going to check off Ada and click continue then I'll click okay and you can see here we have the case processing summary that comes up first we have 45 observations no missing values and you can see here at the the treat M times depression cross tabulation that for the treatment we have the rows individual group and treatment as usual and then for the columns we have all the values that appeared in the depression variable you can see all the counts associated with those values and then under directional measures nominal by interval Ada you can see that has two values here one where it treats the treatment variable as the dependent variable and one where it treats the depression variable as the dependent variable and we know in this case of course the depression variable is our dependent variable so we're going to interpret this value and this is 0907 now Ada values range from zero no association to one which is a perf Association so value of 97 is a strong association between these two variables to calculate Ada squared we would Square the Ada value here and the Ada squared statistic will tell us how much variation is explained in the dependent variable by variation in the independent variable so I'm going to move the output here a little bit to the right bring up the calculator and I'm going to move into this table and double click and then double click on the Ada value for depression being treated as a dependent variable to get a precise value of ADA I can see it's n07 317 so if I square that I get 823 224 that's my Ada squared value now you may recognize that in a NOA there's a statistic reported named partial Ada squar now partial Ada squar is a different statistic than Ada squared Ada squar is the sum of squares between divided by the sum of squares to total and partial Ada squ is the sum of squares between ID the sum of squares total plus the sum of squares error however for a one-way an NOA the value of ADA squar and the value of partial adaa squ will be equal so if I move up here to analyze and go to General linear model univariate and place treatment as a fixed Factor independent variable and depression as a dependent variable then under options check off estimates of effect size and click continue and then click okay we can see that we get a partial Ada squared value here of 823 and again if I double click on this table and double click on the actual value you can see it's 8232 224 so I bring that calculator back over you see it's the same value so in this case because we're working with one way a NOA the value of partial Ada squ is equal to Ada squ that will not be the case when working with more complex models Ada squar is a measure of effect size so when we're interpreting Ada squ one of the popular guidelines is that a value of 02 or 2% is small .13 or 133% is medium and. 26 or 26% is large so in this case because we have an ADA squared value of 82% we would consider this effect size to be large I hope you found this video on calculating interpreting Ada and Ada squared and SPSS to be helpful as always if you have any questions or concerns feel free to contact me I'll be happy to assist you