midterm 1 material Flashcards
what are latent constructs
seek to identify the properties of a psychological object
latent: can not observe it
construct - domain of behaviours
example: working memory
What is a test - be specific
Measurement device or technique used to quantify behaviour or aid in the understanding and prediction of behaviour
composed of ITEMS
What are the steps of creating a test?
1) conceptual foundation
2) purpose of the test
3) table of specification
4) select attributes of the construct
5) select population of interest
What is pilot testing and why is it important?
a small scale study where a sample is selected in order to validate our test
two main objectives:
1. obtain statistical information on items
2. obtain comments to improve the test
key: to examine psychometric properties
nominal data
- categorical
- can not rank/order the categories
- zero is NOT meaningful
= can not apply mathematical operations on the data
example: ethnicity, marital status, province of residence
ordinal data
- categorical
- can rank/order the categories
- zero is NOT meaningful
- can not determine distance bw categories, cant apply mathematical operations
example: income categories, likert scales
interval data
- continuous
- can rank the values
- zero is NOT meaningful
- can only apply addition and subtraction
ex. Fahrenheit temperature
ratio data
- continious
- can rank the values
- zero IS meaningful
- can describe differences bw values
- apply all forms of math (divide, multiply, subtract, add)
ex. personal income, age, time
Properties of correlation coefficient
dichotomous items
only two response options
- true/false
- requires absolute judgement that is either 100% yes or 100% no
- no middle
polytomous items
have more than two response options
ex. multiple choice test
- good balance of ease administration
- wrong answers are called distractors
What is difficulty and optimal difficulty?
difficulty: property indicating the probability of success/failure for each item
- ex. percentage of correct and incorrect items
optimal difficulty: Chance + (Perfect – Chance)/2
- It is the point where the task is neither too easy nor too difficult
What is a carry-over effect?
where information gained by writing the test carries over to the second time writing
- hard to guarantee no carry over effect is occurring
- when consistent no impact to reliability
- test retest is typically not a primary method of
reliability estimation
What is Readability?
indicates whether the test items require a reading skill level beyond what
would be expected for the population
Why do you standardize scores / create a standardized score for your measure?
