Exam 11: Correlated Groups T-Test

The correlated groups t test provides a less sensitive test of the relationship between the independent and dependent variables than does the independent groups t test.

One procedure for venly distributing carry-over effects across conditions is called counterbalancing.

Dr.August is investigating whether or not women have more job satisfaction after they are given praise or a gift card (different levels or rewards).She has recruited 10 women from Intel and for 6 months the women received praise then the next 6 months they received a gift card.The conditions were counterbalanced and a survey on job satisfaction was distributed following the treatment conditions or every 6 months until the research was completed.After finishing her study Dr.August was busy writing a grant,therefore she has asked you to analyze her data below.Please note the survey was based on 1-5 Likert scale with high scores indicating high job satisfaction and low score indicating dissatisfaction. What is the nature of the relationship in Dr.Augusts' research?

The correlated groups t test is typically used to analyze the relationship between two variables when the independent variable is between-subjects in nature.

Which of the following assumptions may be violated if a very large sample is used?

In a correlated groups t-test it is not necessary to calculate the strength of the relationship.

Counterbalancing is a method to control for

If you were limited in the number of subjects you could recruit it would be more advantages to use a ____________________compared with an independent groups t-test.

Dr.Hinson wants to investigate if rats fed a diet enriched with omega will do better at a maze learning task then when these same rats are given a normal diet.He has a total of 30 rats for his experiment.What should Dr.Hinson do before he starts his experiment?

It is possible to obtain a large value of eta-squared without obtaining a statistically significant t value.

The procedure of _____ may be used in order to evenly distribute carry-over effects across conditions.

Dr.August is investigating whether or not women have more job satisfaction after they are given praise or a gift card (different levels or rewards).She has recruited 10 women from Intel and for 6 months the women received praise then the next 6 months they received a gift card.The conditions were counterbalanced and a survey on job satisfaction was distributed following the treatment conditions or every 6 months until the research was completed.After finishing her study Dr.August was busy writing a grant,therefore she has asked you to analyze her data below.Please note the survey was based on 1-5 Likert scale with high scores indicating high job satisfaction and low score indicating dissatisfaction. Which of the following statements best describes results of Dr.Augusts' alternative hypothesis?

The analysis of the nature of the relationship for the correlated groups t test involves examination of the mean scores for the two conditions.

Because the correlated groups t test involves the analysis of nullified scores,the question of the nature of the relationship is not meaningful.

For sample sizes of 40 or more,the correlated groups t test is quite robust to violations of the normality assumption,even for distributions exhibiting considerable skewness.

The standard deviation of the sampling distribution of mean difference scores is referred to as the standard error of the difference.

A psychologist examined the relative effectiveness of 2 therapy techniques for the treatment of seasonal depression.A sample of N=5 individuals who display moderate winter depression participated.Each subject was exposed to both light therapy and traditional cognitive therapy at different times.Treatments were counterbalanced to control for order effects.Following their treatment a survey was given measuring depression level.Therefore the dependent variable is a measure of depression after therapy via a questionnaire (1=not depressed 2=some depression 3=neutral 4=not depressed 5=happy. a. b.Is there a significant difference in the effectiveness of light therapy compared with cognitive therapy? Use a nondirectional correlated groups t-test with the alpha set at 0.05. c.Compute the value of eta-squared.Do your results indicate a weak,moderate or strong effect? d.Discern the nature of the relationship between the types of therapy.Which therapy is more effective? e.Write an APA results section to the data above.Remember to include the means and Standard deviations.

Jake is working on his thesis and has two groups of subjects.A total of 10 subjects listened to music at 80 decibels which is considered loud.While the other 10 subjects listed to the same music at only 30 decibels which is soft.After 1 hour each groups was given a hearing test.However,he matched subjects before they were put into groups on hearing abilities.What statistical test should be used to analyze the data?

When using the correlated groups t test,it is assumed that the _____ is normally distributed.

Based on the Method of Presentation section of Chapter 11,suppose a researcher is reporting the results of a correlated groups t test.If she obtained a t value of 2.17 with 10 subjects in each group using an alpha level of .05 and a nondirectional test,how would she report this in a psychological journal?