Module 4 Section 2 Flashcards
Measurement
-assigning numbers to represent the amount an attribute present in a person or object
Advantages of Measurement
- Removes guessing out of gathering data
- tends to be more objective
- reasonably precise
Errors in measurement
-measurement errors are systemic and random error associated with a person’s score on a measure, reflecting factors other than the construct
Common factors contribute to measurement errors
1.Situational contaminants
-awareness of observers may affect their behaviours
2.Response-set biases
-characteristics of the respondents can interfere with
the accurate measures of target attribute
3. Transitory personal factors
- fatigue, hunger, anxiety and mood can affect
motivation to cooperate
4.Administration variations
-altering collection methods can alter results
5. Item Sampling
-sampling of items used to measure a characteristics
can contribute to error
Reliability
- the accuracy and consistency of a measuring instrument
Stability
-the ability to give consistent results when the same people are tested at different times
Measure with test re-test reliability
-researcher gives the same test to a sample on 2 occasions then compares the results
Reliability coefficient
-measure reliability with values between 0 to and 1. higher is equal to more reliability
Limitations of test-retest
-subjects remember the items being tested
-traits of interest change over time
-repeating could change response given
-repetition could bore the participants causing them to
respond differently
Internal consistency
-extent to wich all items on an instrument measure the same critical variables or attributes
Measuring techniques
Split half technique
-split it into 2 halves to make comparisons
Spearman brown formula
-used to calculate the correlation coefficient
Item total correlations
-correlation between each item and total item. above
0.25 are acceptable
Kuder-Richardson (KD-20)
-yes or no response
Cronbach’s alpha
- coefficient measure in likert scale with each other simultaneously
Equivalence
-the degree to wich 2 or more observers using a single instrument obtain the same results
Validity
-an instrument measures what it was suppose to measure
-it addresses the question of how well we measure social reality using our constructs about it
4 major types of validity measurements
1.Face validity
2. Content Validity
3. Criterion-related Validity
4. Construct validity
Face Validity
-looks like it is measuring the target construct
Test for with: expert opinion and panel of experts
Content Validity
-extent the instrument covers the factors or situation under study
Test for with: verify with other evidence