- Thread starter jimbrowsky
- Start date
- Tags assumptions confidence interval correlation paired t-test t-test

Name the dependent variable and its scale of measurement?

Number of assignments not turned in by students after treatment

Number of assignments not turned in by students after treatment

Do positive suggestions versus negative feedback affect the number of assignments completed by a sample of eighth grade students?

1c) Describe why the psychologist selected this statistical test?

To determine whether positive rather than negative feedback affect future completion of assignments.

To determine whether positive rather than negative feedback affect future completion of assignments.

List the statistical assumptions for this design.

There will be a correlation between positive and negative feedback and missing assignments. The variance from each treatment will be equal. Students will have less missing assignments after receiving positive feedback rather than negative feedback.

There will be a correlation between positive and negative feedback and missing assignments. The variance from each treatment will be equal. Students will have less missing assignments after receiving positive feedback rather than negative feedback.

Rather, stick to the assumptions of the dependent samples t-test. And read carefully.

Maybe there's a difference between independent and dependent samples t-test, e.g.

regarding equality of variance assumption. And your use of "correlation" here might

distract you from more important topics.

Discuss the strengths and weaknesses (e.g., violations of assumptions) of this study's design.

assumption can be ruled out.

Students missed assignments less after receiving negative feedback (Mean = 7.25, Std. error .479) rather than positive feedback (Mean = 3.50, Std. error = .645, Correlation = .135, Paired diff. Mean = 3.750).

v) Provide an effect size measure, which may require part-hand calculation, and include your interpretation in your conclusion (above).

There was no significant change in students feedback from the psychologist.

There was no significant change in students feedback from the psychologist.

Provide confidence interval results for t-tests and post hoc tests from SPSS output only.

Regards

K.

I took regression and ANOVA over a year ago in my graduate program (and learned the former to some extent over two decades ago). Only next semmester will I finally take experimental design. It should be the other way around.

This reminds me of what I have long thought an anomaly in methods. Its common to learn methods and not learn the experimental design that allows you to understand how to set up the experiment - which is commonly the most important part.

"I have performed an ANOVA. Now tell me something about the interpretation of

technical detail XY" , not "I am studying XY, I set up a study with design XY and

measured XYZ, my sample size is NN, and now I want to answer questiion XY..."

Regards

K.

.

It lacked 10 participants & was not normal, so it is a relatively useless study?

was not normal" and/or where you know it from that something was not normal. And a study is not useless

only because a certain statistical technique cannot be used to analyse its data.

Regards

K.