Pretest and Posttest Data Analysis with ANCOVA in SPSS

[@thecorgisquad9861]

It is so much more helpful for me to understand not only ANCOVA, but other statistical measures as well, when Dr. Grande uses pre- and posttest examples. I think seeing the assumptions tested twice on the same population really drives the point home (i.e. if you're confused during the calculation for pretest, pay closer attention during posttest).

[@marisamaguire8136]

This demonstration really allowed me to obtain a better understanding of pretest and posttest analysis. It was beneficial to learn that ANCOVA controls for the pretest values, allowing us to view the posttest values to determine if there is a significant difference between the control and treatment group. I can see how the use of ANCOVA to analyze pretest and posttest data permits researchers to establish whether or not the information being tested is helpful to the groups being assessed.

[@nelisafreitas739]

Dr Grande you are resourceful. You have helped me so much. I discovered you in 2015 and I am just so grateful. I am almost at the end of my PhD journey and I think you are brilliant.

[@DrGrande]

Thank you for your kind words.

[@cherylchance904]

The detailed explanation of the variables helps me to gain a better understanding of why we chose to use this form of analysis. Sometimes I get confused with regard to which data analysis to select. These introductions help to provide me with appropriate clarification.

[@aliciazahn1718]

I never realized you could just highlight two of the variables you want to look at an it will run them both (or I suppose more than two, even) together. It's great to see how to control for the pretest, the only reason you run this test. This really puts into perspective how one can control for the pretest effect without using the Solomon research design.

[@carolkirby9558]

Very helpful. Dr. Grande is always able to put complex concepts into practical, much easier to understand terms and explanations.

[@jazzynovy5400]

When learning about pretests and posttests in undergrad, I still agree that a study should have both to find any differences before and after a study has been conducted. I think that even though you are trying to test if a treatment is effective, it would be beneficial to compare the posttest and pretest if the treatment has made a significant impact. This video was helpful in explaining the usefulness and how to analyze the data.

[@jpincinjr]

Jasmine Aviles Well said, Jasmine.

[@cassiemclaughlin9489]

I have recently become interested in pretest and post-test analyses. I have also become more familiar with ANCOVA and was unsure of how this worked together. The video helped clarify this and increased my interest in research.

[@danielleduboski9831]

This video helped me better understand why pretesting and postesting is important. it was helpful to see where the control and treatment groups varied.

[@rebeccameece013]

Danielle Duboski I was happy to also see where the control and treatment groups varied. This video was really informative and it was nice to grasp a better understanding of pretest and posttest from watching the video.

[@brittanyhoffman8068]

Thank you for sharing this video Dr. Grande. I like using pretest and post test data to see if what we are testing is actually helpful to the group we are assessing.

[@Chloe-cm1ur]

It is really helpful. I haven't learnt ANCOVA in lesson before but I need to propose ANCOVA in my intervention proposal. You clear my doubts. Thank you very much!

[@jacklinskibicki6098]

This video does a great job explaining the usefulness of pretests and posttests, and demonstrates how to then analyze the data. In my opinion, it would be ideal to use pretests and posttests whenever possible, as I feel they are beneficial in determining group or treatment differences within research.

[@jazzynovy5400]

Jacklin Skibicki i agree. it's helpful to make a comparison to see if the treatment was actually effective

[@tamarabakergibbons5715]

So it is important to run an ANOVA before the ANCOVA. Pretest and posttest data appears simple, but it's actually not. Once you know that you can control for covariates and other factors, the data can be useful in many other ways. Thank you for the video.

[@reginaames3038]

Pretest and post-test is in my opinion usefull information in order to see differences in control group and treatment groups. Great information.

[@ariadnaaguero-roman5525]

This is important tool to use in an experimental design or any other design with a pre and post test. I like that it compares between control and experimental group and determine if there is statistical significance and test for assumptions.

[@dHunter94]

This video was so beneficial to watch. This explanation was everything that I needed to ensure I explain the analysis section of my group's research paper accurately. Thank you for posting!

[@jessedarwin7615]

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[@koaalijah8294]

@Jesse Darwin instablaster =)

[@jessedarwin7615]

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[@jessedarwin7615]

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[@koaalijah8294]

@Jesse Darwin Happy to help =)

[@katherinebeck593]

I still think that excel is easier for me to understand personally but the explanation of this process was pretty straight forward and helped me to understand what an Ancova is used for.

[@mandabear52289]

I think that SPSS is much harder to understand via video than learning it in person. I think you would find that SPSS is really a language of its own. Once you learn it though, it becomes much more user freiendly than at first glance. Hopefully one day you will get a chance to use it in person!

[@dalietamears7116]

This video was helpful in understanding how to control for the pretest and the outcomes on the post test using ancova. It gave me insight on how to use ancova.

[@MarkVanderley]

I am thankful for the introduction to the additional assumptions required when running an ANCOVA, had not learned about those to this point.

[@angiegrimes7265]

I found this video did a good job in explaining what an ANCOVA does. This will be useful in helping me pick out the cappropriate statistics for my research project.

[@rajninaiyyer5478]

Sir Thanku so much I am new student My strim is humanity. So please teach very easy way I am from India🇮🇳 I am your bigger fan.

[@sansarrra]

You are the best Dr Grande ❤❤❤

[@vanessagraham6473]

So good to note the power of the test but also its limitations (to answer just the one question).

[@susanwilder7616]

I can see this being very a very popular analysis function to use. There was a lot of good information in this video. If I were actually conducting my experiement, it would certinaly come in handy.

[@amandachaffin6636]

I am glad that at the end of the video you described when it would be appropriate to run an ANCOVA compared to other statistical data.

[@cassieperoulis4881]

+Amanda Sutton, I agree! It made sense when it was explained as to when it would be appropriate to use the ANCOVA vs. other data.

[@1515Desiree]

+Amanda Sutton Yes! Very good to know when to run the ANCOVA.

[@heather7927]

You make a great point with using the Ancova as opposed to using the statistical data. I liked how this video showed the control group and the treatment group and it's able to be viewed through the chart. It was a great visual.

[@rebeccameece013]

I really liked seeing the pretest and posttest examples because it may be something that I want to do for my research proposal. I feel like I was able to follow the video pretty well and I really liked to see how to rule out covariates.

[@lisanoland5134]

Thank you for this information, since our research is based on comparing pretest and posttest scores this information will be helpful for our group.

[@melissaclendaniel9811]

Watching this was interesting and not just because I like statistics. I will be doing a pre test and post test in my research paper and I am glad I was able to see step by step how this is done

[@reneemendez4287]

Melissa Clendaniel I'm also using a preteset and posttest in my paper so I think think video will come in handy. Especially because it was broken down into step by step processes.

[@kimberlykelly386]

Pretty interesting video, learning more about SPSS! Being able to use ANCOVA is conditional; certain assumptions have to be tested. I'm learning that you run the univariate tool to test those assumptions and it's nice to walk through how exactly to do that. I'm sure this will come in handy in the future if/when I'm working in the SPSS program.

[@timandonopiyo]

Thanks a lot Dr. Grande, I just got a solution to a problem that has been bothering me for long

[@scottmartin7764]

This is very detailed and at first very intimidating but I think over time and with practice I will be alright. I think the key is to make sure you follow the steps correctly and with more experience I will be fine.

[@pearlbutler9377]

I hope you are right, Scott. All of this is causing me anxiety.

[@charmainequarles5863]

You said we'd be fine but tomorrow is the last class and I'm wondering if that is true.

[@MrsBobDylan]

I think that this video helped me to understand ANCOVA a little more and how to use it. I'm still a little confused because I'm not really good with research and all the tests and terms, but this did help me understand more.

[@Mjthfdj]

I am using pre and post tests in my research paper so this helps. I actually prefer a pre and post test as a way to analyze the differences in the starting point and the outcomes. I am more familiar with Excel but it was nice to see it done in SPSS.

[@mandabear52289]

The part that I found most interesting is that in the video the co-variate that we contolled for was the effect of the pre-test. I never would have thought to do that. I really thought that was neat. It may be something that I would do with my research proposal as well because mine is a within subjects design.

[@tammywitzke6642]

Very clear instruction on ANCOVA.

[@ivybyun2791]

Thank you for the reminder to consider the research question when analyzing the data.

[@AnnaLaura1011]

this was a very good overview, but definitely something i am going to have to study further

[@kimberlydixon8760]

I thought this video was really interesting and it was nice to see the pre and post tests to see the differences between the control and treatment groups.

[@nelisafreitas739]

Thank you so much Tedd your video's are empowering. I appreciate the way you take time to explain concepts. I have learnt a lot from you.

[@DrGrande]

You are welcome - thank you for watching -

[@thomasstarr6433]

Processing the steps and aspects of the assumptions was very helpful.

[@ashleydorsey6745]

Pre and post tests are extremely important. It helps to see if there are any variances in the data collected during the research. Also the data gathered pre and post test can be used as a comparison when noting the findings/conclusion in the research design.

[@paulhoard7390]

I strongly agree with Thom. This is very helpful.

[@surfergirl0519]

Thank you so much for this video. It helps so much. I was struggling with how to set up my data and you made it really clear. I would love to see how you would write up these results.

[@siminguo6562]

Thank you so much for your video. It is very helpful. I am really grateful.

[@reneemendez4287]

Like many others I will be doing a pretest and postest in my paper so I found this video very interesting. I liked seeing how to use ANCOVA to do this although I still find ANCOVA to still be a bit confusing.

[@bethanyelstrom3566]

This would be great to use in my research project. This is a simple process to see if there is a significant difference in groups based on posttest results.

[@daniellemaldonado631]

Bethany Elstrom Yes, this would be great to use for my research proposal as well. I can test to see if a group getting CBT and Therapeutic Horseback Riding is more effective than CBT on its own. LOL.

[@rachelfoster5463]

I liked learning how to use a pretest posttest analysis with ANCOVA. My research project will require a pretest posttest, and it is interesting to see how to run one of these tests. I may also have a covariate to rule out, which makes this video helpful for me.

[@ashleydorsey6745]

Rachel Foster My research also requires a pre and post test. This video helped explain how I would use ANCOVA in SPSS to see the statistical significance.

[@kimberlykelly386]

***** Great point. It's interesting, too, that we tend to want to see non-significance when testing the assumptions.

[@aliciazahn1718]

Rachel Foster Yes, that is a good idea. I wonder how often covariates are measured and tested for or even how often the ANCOVA is used to control for the pretest. I've never taken notice when reading research articles.

[@ariadnaaguero-roman5525]

i agree. This will definitely help to chose tools to measure data for the research project.

[@afuaampiaw6308]

This has helped a lot. Thank you Dr. Grande

[@toniettemorda6247]

Pre and Post Test score is interesting to use when one would like to see a difference in a particular population. The ANCOVA will control values to see if there is a significant difference between the control group and experimental group

[@MichaelSmith-jd5ki]

I like seeing another example of controlling a covariate using ANCOVA and one specifically, controlling pretest data, seems very useful for real-world application.

[@danielleduboski9831]

Michael Smith I agree about pretesting. If you don't have a base live to go from I think even if your results show a difference you are not getting the whole picture.

[@mirandat1087]

I really liked this video because I can relate it to my research project. This would be great to view if I were to actually conduct the experiment and help me do calculations step-by-step.

[@meizamaulida9582]

Thank you for the great explanation, Doctor! I wonder how to add that Profile Plots graph since I couldn't find it when I use SPSS 26 🤔 thank you in advance!

[@brittanyvodzak9198]

Easy to understand and I think I would be able to do this if I was working is SPSS. I get confused when the test comes up on a different screen with the test results. When using Excel I like that everything is pretty much done in one screen. I think Dr. Grande was able to explain it though in terms that I could understand.

[@CandyKaneLane]

Brittany Vodzak I also like having everything on one screen, it keeps me on track and helps to steer away from possibly making an error or missing steps.

[@chelseydavis4989]

Brittany Vodzak I agree with your statement regarding the one screen. With so many other details and components to keep track of, I like to keep what I am viewing as simple as possible so I don't miss something key or confuse my information.

[@kimeeshareedwalker2602]

This does seem straight forward. Once I explore SPSS a little more and get familiar with all the features, it seems like after the test scores are recorded the program does the configurations.

[@bradleyfairchild1208]

I watched this to help with assumptions and it was very helpful thanks.

[@andrewwilson6604]

i actually learned a lot from your video

[@prowan6294]

Exactly what I need to analyze in my research. Thank you

[@simonehenry469]

great examples in the video.

[@rasinrs]

Sir, it is very useful for a beginner like me. My doubt is in my data consisting the variables more than one post test. Then how do I analyse the data. I usually prefer REPEATED ANOVA.but I have both control and experimental units. Thank you for your responds

[@ruslanmapeala5635]

Thanks a lot Dr for this video..really appreciate it.

[@claribeldao-ayan5871]

thank you...it helped me a lot in analyzing the data of my research.

[@yitayaldamtew5491]

very very very helpful.

[@kreitzberg09]

Thanks for posting this!

[@DrGrande]

You're welcome, thanks for watching -

[@kyarapanula1002]

I'm now seeing the importance of using the right model of pre- and posttest score anaylsis....

[@aprilbrooks8672]

I understand this model of test more and more with repetition, when we add C to the Anova that means we are controlling a covariate and checking to see if there is a difference between IV groups and the other DV in the data

[@stevieporter3399]

I agree, this video really helped me clarify some things in my head, and it makes this process more clear.

[@sarahburrous7374]

I understand the significance of wanting to control the pretest and comparing the two groups to the posttest only. When would you want to not control the pretest? Would this be a comparison between the pretest and posttest- would that ever be something you would want to look at?

[@jhoward1129]

I wish that this video was in Excel so I could try it. I will be using pre-test and post-testing in my research proposal, so I'd like to know how to do it in the program I have just for fun. I like the example given in this video. It made the video more applicable to something I can understand. I also have covariates I would need to rule out if I actually did my research proposal, so this was interesting to see.

[@rachelfoster5463]

Jessie Howard I wish it had been in Excel too! Many of us seem to be using the pretest-posttest in our research proposal. Therefore, being able to see that in Excel would have been beneficial.

[@bethanyelstrom3566]

Jessie Howard This video is a great example that we could use in our research project. Very simple to run once the data is entered into the fields.

[@susanwilder7616]

Jessie Howard Seeing how it's done in Excel certainly would be helpful considering it seems that a majority of the videos were made in Excel as well. Consistency is key.

[@thecorgisquad9861]

Jessie Howard This would be great if it were an Excel example, especially, as you mentioned, most, if not all of us will be using this type of statistical measure in our research paper! I'm sure if you propose this to Dr. Grande, he will be more than happy to oblige your request.

[@farzanmadadizadeh3838]

Than you indeed!!

[@DrGrande]

You're welcome!

[@jessjam9451]

Great vid- for within subjects/repeated measures design what would be different?

[@pghjmuhammadfirdauspghjrus2693]

Thanks a lot

[@hilmiyahzakaria3320]

thanks for the video. I really appreciate it.

[@guillermomolina6884]

Really interesting. Thank you so much!!

[@michellerobinson968]

I took from this video that the ANCOVA controls the pretest and tells us if there is a difference between the 2 treatment groups. This is the only question it answers.

[@simonehenry469]

Michelle Robinson good observation and summary.

[@marjoriekionisala5597]

thanks for your video. it's very helpful for me who never encounter ANCOVA before. i just want to know how to interpret the results then. :D thank you

[@blessingakarue9010]

Dr, thanks fro the lecture but if the assumptions are not met what do we need to do

[@hrushikeshdas5447]

Hello Sir You have made it very easy to understand Can You Please Help me How to represent this data in tables and graphs

[@aussiebreezekorb8877]

I think I still prefer Excel, but this was helpful in considering statistical significance and posttests.

[@corieschoeneberg9295]

Very helpful

[@CandyKaneLane]

I personally like having pretest and post-test in order to see the differences that treatment and non-treatment can have. As I was able to follow you throughout this video, I am wondering what the major difference in doing this in SPSS versus Excel is.

[@toniettemorda6247]

Candace Fernandez I liked this video! Testing pre and post a study has always interested me to see how growth is occuring in either group

[@reginaames3038]

Toniette Morda Yes seeing the growth is great information

[@jacklinskibicki6098]

Candace Fernandez I agree, using a pretest and posttest is useful in determining differences, and I feel they should be incorporated into a research design whenever possible.

[@jhoward1129]

Candace Fernandez I'd like to see how Excel would look and work too, considering most of us "common folk" don't have SPSS at our disposal.

[@melissaclendaniel9811]

I was wondering the same thing as I watched this because most of us do not have access to SPSS.

[@andrewwilson6604]

hello Dr. Grande, thank you for the video can you please do an experimental study SPSS using pre and post test along with other variables that are also pre and post?

[@jpincinjr]

This would be helpful in research to see the covariance between the pre and posttests.

[@sueramli7602]

thank you so much for the information

[@jaylieberman3114]

Thank you! So helpful

[@DrGrande]

You're welcome - thanks for watching -

[@mdaltinisik]

Hi Dr Grande. Is there any conflict about the assumption of covariant must be unrelated to the independent variable to perform an ANCOVA? If not, how can we analyze the effect of A on B, free from C? (A = categorical (2 categories, independent) variable B = numerical (dependent variable) C = numeric (covariant variable) Both B and C appeared significantly different between the two groups according to t-test.)

[@MuzMovMix]

My question is how to interpret the effect of covariate on the posttest? For example, if it is positive correlated, how could you tell such correlation?

[@saraspong6698]

Thank you!

[@matuskrcmar7629]

Hellou Todd your videos are really good and helpfull. But I have question about post-hoc test. How Can I conduct this post-hoc correction if I want to see exact differences within one of two group? not only main effect. Thank you very much for any response.

[@cherylchance904]

Great question Matus. I would like to see a video on this if there isn't one already. Perhaps we should search You Tube videos by Dr. Grande as he is pretty thorough with regard to ensuring he has covered all of the different options.

[@Amys_Garden]

Thank you :)

[@nicolewalton6155]

Helpful, thank you!

[@daniellemaldonado631]

So, the ANCOVA for pretest and posttest data analysis will control for the pretest values in order to let us see if there is a difference between the two tx groups. This is becoming easier.

[@peterizuobaokoye8295]

This is great. Thanks. I would like to have the video.

[@DrGrande]

You're welcome - thank you for watching -

[@joe1579]

So ANCOVA is useful to look directly at whether the treatment effects the dependent variable by comparing the two groups outcomes; & can be used as long as there is no meaningful differences that could effect it from another variable, such as the pretest...

[@jazzmynmolson307]

It seems that would be a good way to sum it up. I believe this is more effective for research looking specifically at treatment before and after if we are looking at levels of significant differences...?

[@cathkids1680]

Dr. Grande, so how should the analysis be done if there are 3 time points?

[@MyDonh]

Dr Grande does a great job of explaining this procedure. However i am starting to see the need for a study group. Anyone interested?

[@kyarapanula1002]

don, you read my mind! how can we strategize on this....meet in one of the labs before class?

[@angiegrimes7265]

I too think it would be a great idea to meet

[@vanessakent8700]

I noticed that you did not run the IV without the co-variance as you did in the previous video. Any particular reason or more due to the type of design- pre-post test?

[@elaine901]

Hi there Dr Grande. Is there a way to obtain a table of multiple comparisons when performing an ANCOVA? My independent variable has three levels (different treatments) within it, my dependant variable is treatment score after, and my covariate is treatment score before. I am wanting to look at the significance values of these treatments but am lost as I am only given a test of between subjects effects which only gives a significance value for all three treatments and so the significance of each treatment against one another is unknown. I am quite new to using this program and perhaps am using the wrong type of analysis. Any advice would be amazing! Thank you.

[@quanthanhhuynh5669]

Dear Dr.Todd, What if the second assumption is not met?

[@orochimaru2010]

I did exactly as illustrated on the video and got (.203) sig value for the pretest. Is it significant? Also, is .834 not significant in the same context? Where is the cutoff point?

[@hannahnurit]

This also works if there are more than 2 condition groups, right? (e.g. i have 3 experimental conditions and 1 control group hence 4 groups) thank you

[@nashdasmurayan1975]

if there are 3 levels of the independent (experimental, placebo, control) variables, do the steps above remain the same or is there anything that we should be aware off?