lecture 5 notes exam 1 Flashcards
conceptual variable/construct
the high-level abstract idea, e.g., happiness
conceptual definition
Your definition of the construct: ex: subjective sense of well-being (definition of happiness)
operationalization
ways the construct can be measured, e.g., asking people how happy they are from 1 to 10
How could you operationalize the construct of anxiety?
measuring heart rate, looking at speech patterns, how much they are sweating, their sleeping patterns, asking someone to rank their anxiety on a scale
3 common types of measures
- Self-report: ranking on a scale or asking someone how many anxious moments theyve had this week
- Observational measures (behavioral measures), e.g., stuttering during a conversation, how many hours they sleep, fingernail biting
- physiological measure: sweating, saliva (cortisol levels)
examples are related to measuring anxiety
what does it mean if a measure is reliable?
it is consistent
what are the types of reliability?
test retest
interrater
internal
what is test-retest reliability?
consistent scores everytime the measure is used, ex: someone will have about the same score today tomorrow next week or next year
comparing time 1 and time 2
what is interrater reliability?
consistent scores no matter who measures. A measure has high interrater reliability if 2 people using the measure get similar scores for the same participant
comparing rater 1 and rater 2
what is internal reliability?
consistent scores on different versions of questions
a measure has high internal reliability if a participant provides a consistent pattern of responses regardless of how the researcher phrased the question
comparing question 1 to question 2
How can we visualize reliability?
scatterplots (the closer the points are to the line, the more reliable) and correlation coefficients (more reliable than scatterplots)
in what reliabilities are scatterplots used?
interrater reliability and test-retest reliability
correlation coefficients (r)
ranges between -1 and 1
any r value greater than 0 is positive anything below 0 is negative
strong associations are closer to -1 or 1; weak associations are closer to 0 (test-retest above 0.5, interrater above 0.7)
where would we expect high association vs low association?
scales of measurement
nominal, ordinal, interval, ratio
categorical/nominal scales
Categorical/nominal variables: levels are qualitatively distinct; order doesn’t matter
- e.g., social media apps: TikTok, Snapchat, Instagram,
Facebook.
- current TV shows on netflix
ordinal scacles
Ordinal: ranked order
- Numbers corresponding to each level are meaningful.
- The distance between the levels doesn’t matter
Examples
- Place in a race: 1st, 2nd, 3rd. the distance between first
and second could be 10 seconds apart, and the distance
between second and third could be 4 seconds apart
- socioeconomic status
interval scales
Interval scale: equal distance between levels
- numbers corresponding to each level are meaningful
- the distance between the levels DOES matter
- there is no true 0; a level of 0 doesnt mean theres no
variable present
Examples
- jeans sizes: size 0, 2, 4, 6 (a size 0 doesnt mean the
person has no waist
- the year you were born
ratio scales
Ratio scales: equal distance between levels and 0 is meaningful
Examples:
- Asking someone how many cats they have. If someone has
0; they have none If someone has 4, they have 4
- number of classes you are taking
inter-item reliability
usually 2 or more items in a survey so one correlation coefficient isnt enough
validity of measurement
- Face/content validity
- Criterion validity
3.
face/content validity
Does it look like a good measure, subjectively?
face validity: it looks like what you want to measure, ex: a math test looks like a math test. high face validity
content validity: it contains all the parts that your theory says it should contain ex: the math test only contains addition and no other things like subtraction and division so low content validity
criterion validity
What is your measure supposed to predict?
Known groups paradigm: examine whether scores on your
measure meaningfully differ between groups whose behavior is already well understood