A weighing scale adds exactly to every measurement. Determine whether the measurements are reliable, valid, both, or neither, and justify your answer.
[4]A final exam omits half of the course topics. Identify which type of validity is compromised and explain your reasoning. [3 marks]
[3]Six students’ SAT scores (out of 1600) and their first-year GPAs (out of 4.0) are:
.
Compute the Pearson correlation coefficient and comment on the predictive validity of SAT scores for first-year GPA.
[6]The question assesses understanding of validity in psychological research methods, specifically focusing on identifying and explaining convergent (or concurrent) validity within a measurement context.
A new anxiety inventory correlates strongly with an established anxiety measure. Which type of validity does this demonstrate and why?
[2]A test consists of three items administered to five students. Their item scores are shown in the following table:
| Student | Item 1 | Item 2 | Item 3 |
|---|---|---|---|
| A | 4 | 5 | 3 |
| B | 3 | 4 | 4 |
| C | 5 | 5 | 5 |
| D | 2 | 3 | 2 |
| E | 4 | 4 | 4 |
(a) Calculate Cronbach’s alpha for the internal consistency of the test.
(b) Interpret the value obtained in part (a).
[6]Two examiners independently grade essays on a scale and their scores are highly consistent. Identify the type of reliability and explain your answer.
[2]The Scholastic Assessment Test (SAT) is a standardized test widely used for college admissions in the United States. Its primary purpose is to measure a student's readiness for college and provide a common data point for comparison.
A cohort of students with high SAT scores earn low GPAs in their first university year. Identify the type of validity concern and justify your answer.
[2]Five subjects’ weights were measured twice by the same scale. The paired measurements (in kg) are:
Compute the test–retest reliability coefficient using Pearson’s and interpret the result.
[6]Students who did well on yesterday’s test perform similarly on today’s test (the same test). Identify the type of reliability this scenario illustrates and explain why. [3 marks]
[3]Two raters independently classify 10 essays as Pass (P) or Fail (F). Their decisions form the table:
| Rater B: P | Rater B: F | |
|---|---|---|
| Rater A: P | 4 | 1 |
| Rater A: F | 2 | 3 |
Calculate Cohen’s kappa and interpret the inter-rater reliability.
[6]Five students took two parallel forms of a test. Their scores out of 100 are: Student 1: (90, 88), Student 2: (75, 78), Student 3: (82, 80), Student 4: (68, 70), Student 5: (95, 92).
Compute the parallel-forms reliability coefficient (Pearson's ) and state its implication.
[6]A new happiness scale shows very low correlation with an established depression scale. Name the validity type illustrated and justify.
[2]