lecture 4

Question 1

reliability measures

Answer 1

• test-retest reliability: compare time 1 and time 2
• split-half reliability: two parts of the same test (make sure scores are similar on both halves)
• inter-rater reliability: two (or more) observer’s match

Question 2

are validity and reliability independent?

Answer 2

• theoretically yes, BUT
• it’s impossible to have a valid measure that is not reliable
• a reliable, but invalid measure is all but useless!

Question 3

the barnum effect

Answer 3

• individuals agree with personality descriptions that appear to be personalized or based on results of some test
• vague statements apply to almost everyone
  applications: personality tests, horoscopes, fortune tellers
• cancelled by negative attributes (strawberry)

Question 4

4 scales of measurement

Answer 4

1. nominal scale: data arranged into discrete, not ordered, categories, is there a difference?
   ex) what is your major
2. ordinal scale: data arranged in order of magnitude, what direction is the difference?
   ex) grading scale A, B, C
3. interval scale: measurement has equal intervals: 0 value us arbitrary
   ex) temp
4. ratio scale: measurement has equal intervals: 0 value is meaningful
   ex) scale

Question 5

rating scales in psychology

Answer 5

• should be ordinal, but typically treated as interval
• why is this a problem? Data analysis
• assumes differences between labels are equivalent
• implications for statistical analysis
• still not resolved: researchers are aware of it

Question 6

how do we obtain measurements

Answer 6

1. self-reports
2. asking participants directly
3. physiological measures
4. behavioral measures

Question 7

why use self reports

Answer 7

• ask (almost) anything: perceptions, opinions, behaviors
• useful when behavior cannot be observed ex) past events/relationships
• inexpensive, relatively quick/easy

Question 8

why we shouldn’t use self reports

Answer 8

• don’t want to answer: how often do you exercise?

- don’t know how to answer

Question 9

asking participants directly

Answer 9

True/false, agree/disagree, on a scale from 1-10, how often

Question 10

physiological measures

Answer 10

• measurements taken directly from the body
• heart rate, GSR
• brain scans

Question 11

pros and cons of physiological measures

Answer 11

Pros: objective
cons: expensive, time consuming, alternative explanations, controllable?

Question 12

behavioral measures

Answer 12

• in-lab observations: typical experiment

- naturalistic observations: real-world experiments