Lab Report 1 - The State-Trait Anxiety Inventory (STAI)
The aim of this practical exercise is to introduce you to one widely used psychological assessment tool and also to introduce you to one of the most widely used statistical software packages in the world - SPSS.
Learning Objectives
After completion of this assignment you will:
- Be able to describe the STAI including its purpose, administration, scoring and some important psychometric properties.
- Be able to do basic statistical analyses of questionnaire data using SPSS including - descriptive statistics (mean, median, range, standard deviation, frequency distributions), independent samples t-test, scale reliability (Cronbach's alpha and item-total correlations) and correlations.
INSTRUCTIONS:
• Your lab report must have a title page that includes: Name, Student ID, Paper title and Code Number, Title and number of lab report, date report is due, lab stream you are in, tutor's name. Your name is optional if you prefer anonymous marking.
• Use Times New Roman or Arial font and use font size 12.
• Marks will be taken off for untidy presentation, poor grammar and spelling errors.
• There is no specific word limit as such however your lab report (not including the title page) should be no more than two (2) sides of A4 paper.
• To ensure that every student gets their unique results by conducting statistical analysis individually, you have to create your own, unique data set and use it for all statistical analysis in this lab report, as following:
• 1) Download the STAI Dataset from the assessment folder in Psychological Assessment
• 2) Complete the STAI questionnaire found in the same Assessment folder one more time.
• 3) Add your responses to each STAI item at the bottom of the STAI dataset.
• 4) Email your unique dataset with added responses to your tutor
• Successful completion of this task is worth 1 mark out of 25 allocated for this lab report.
• Failure to create and email your own unique dataset before the assignment due date means that your lab report will not be marked.
Answer each of the following 9 questions:
Q.1 Briefly describe, in your own words, the general purpose of the STAI and its administration.
Q.2 Explain in your own words how the STAI is scored.
Q.3 Using the STAI_PA_566604 dataset calculate the following:
- Mean, median, range and standard deviation for the total score of both State and Trait subscales of the STAI.
Q.4 A student score 35 on the Trait and 55 on State subscale of the STAI. Interpret these scores with reference to your answer to Q3 above. What does the difference between State and Trait scores mean?
Q.5 Examine the frequency distributions of the individual item response scores (1 - 4) for each of the 20 Trait items of the STAI.
- Describe the shape of the distribution typical of most of the 20 items and present onehistogram for one item to illustrate this.
- You can cut and paste the histogram from the SPSS output.
Q.6 Conduct an independent samples t-test to compare total score trait anxiety of males and females and report the results appropriately including both means, t -statistic, degrees of freedom (df) and the p - value.
- Is there a significant difference between males and females?
Q.7 Calculate the individual item-total correlations for each of the 20 Trait items of the STAI.
- Report three items that have the highest item-total correlations including their values.
- Report three items that have the lowest item-total correlations including their values.
Q.8 Calculate Cronbach's α for both State and Trait subscales of the STAI, interpret and compare the coefficients.
Q.9 Calculate both Pearson and Spearman bivariate correlations between State and Traitsubscales of the STAI, compare and interpret the coefficients.
- What coefficient is more appropriate to use with these data by considering the distribution of the total scores?
- What correlation would you expect between state and trait measures and why?