CAS 301 Final Review Guide

Variable: any event, behavior, or individual characteristic that varies - that is, has at least two varaibles

• Specific instances of the variable
• May be quatitative/numberical
• Values, a number with a variable
• May be instances of a category

• Describes the characteristics of a situation or environment
• May pre-exist or be manipulated by the researcer - previous experiment
• To study things that are all ready there
• Predictor Varaible (when pre-exists) or independent variable (when manipulated by the researcher)

• Participant's reaction to the situation
• Behavior/outcome
• Dependent Varaible (when there is an independent variable) or criterion variable (where there is a predictor varaible)

• Individual differnces about the participant
• Pre-exisitng
• Predictor Varaibles

• The dictionary definition
• Explanation or description of a variable

• How you will measure the variable
• Definition in your own words

• Linear Relationship: Relationship measure with correlation coefficient and direction and strength
• Correlation Coefficient: Relationship between two varaibles

• One variable increases, the other variable will also increase
• A one slope = a perfect slope
• EXAMPLE: hot weather/crime rate - as the temp outside increase the crime rate also increase.
• RANGE: 0 to 1.00
• -1.00 to 1.00

• =zero
• There is no systematic relation between the variables

• One variable increases and the other variable decreases
• EXAMPLE: constant discipline increase, the negative behavioral problems will decrease

• Cannot measure with a simple correlation coefficient
• Increase in one variable are sometimes assoicated with an increase in the other variable and sometimes associated with a decrease in the other variable
• INCREASE/INCRASE
• INCREASE/DECREASE
• DECREASE/DECREASE

• No numerical values
• catergories
• basic scales
• names categoreis
• anything you cannot put in order
• EXAMPLE: gender, ethnicity, any yes/no question

• Ordinal Scales: A scale of measurement in which the measurement categories form a rank order along a continum
• Ranked from first to last
• Difference between the categories is not necessarily the same

• Interval Scales: A scale of measurment in which the intervals between numbers on the scale are all equal in size
• Difference between numbers on scale is meaningful
• Interval are EQUAL IN SIZE
• No true zero
• EXAMPLE: temperature

• Ordinal
• ordered rating catergories

• Questionnaires/Surveys
• Interviews
• Observations
• Direct Test

• source error: operational definition isn't consisten - reliability
• Operational definition doesn't match: Validity

• Consistency or stability of a measure of behavior
• The degree to which a measure is consistent

A reliability coefficient determined by the correlation between scores on a measure given at one time with scores on the same measure given at a later time.

• Reliability assessed with data collected at one point in time with multiple measures of a psychological construct.
• A measure is reliable when the multiple measures provide similar reuslts

A reliability coefficient determined by the correlation between scores on half of the items on a score measure with scores on the other half of the measures

• A indicator of internal consistency reliability assessed by examining the average correlation of each item (question) in a measute wiht every other question.
• EXAMPLE: 1 - 2,3,4,5, & 2 - 3,4,5, & 3-4,5

The truth and accurate representation of information about your study and measures

• The degreee to which a measuremtn device appears to accurately measure a variable
• Look at the measure to see if it has "face" value

• related to other things that it should be related to in the future
• Measure something today and compare it to something in the futurer
• EXAMPLE: aggression in 10 year olds and the crime rate in the future
• The construct validity of a measure is assessed by examining the ability of the measure to predict a future behavior.

• Related to other things that it should be related to at the same time
• Done at the same time
• EXAMPLE: SAT scores your senior year should be related to the GPA level
• The construct validity of a measure is assessed by examining whether groupd of people differer in the measure in expected ways

• Similar to other measures of the same thing
• Multiple measures of the same thing
• EXAMPLE: teacher survery of children and observations of the children, they should be the same
• The Construct validy of a meaurse is assessed by examining the extent to which scores on the measure are not related to scores conceptually unrelated measures.

• Different from meaures of other things
• Low relationships between the 2 measures
• Presnonily scores shoud not be related to ones reading aiblity, therefoer, no relationship
• The construct validity of a measure is assessed by examining the extent to which the scores on the measure are not related to scores on conceptually unrelated measures.

The degree to which the results of an experiment may be gernealized