Chapter 2 Flashcards
Define: Theory
a general statement about the relationship between constructs or events.
What 2 characteristics does a theory possess and explain.
- Parsimonious - the simplest theory that can explain the phenomenon is the best. (scientists generally operate under the “law of parsimony”
- Useful - unless a theory can generate testable hypotheses, it will be of little or no use to scientists.
Define: Hypothesis
a formal prediction about the relationship between two or more variables that is logically derived from the theory.
What 3 types of experiments are there? and Define.
Experimental variables
1) independent variable - determines how the groups in the experiments are divided. (treatment variable)
2) dependent variable - is measured by the investigator and used to compare the experimental groups. (outcome variable)
3) Participant variable - inherent in participant, control group.
What is an interaction?
how one independent variable affects the dependent variable depends on the other independent variable.
An investigator who uses a manipulated independent variable does what?
begins with a large number of participants and randomally assigns them to experimental groups.
What is a nonmanipulated independent variable?
this exists without the researchers’ intervention.
Why do researchers prefer to use manipulated variables?
it is difficult to determine cause-and-effect relationships within nonmanipulated independent variables.
What do replications often examine?
participant populations different from those used in the original research.
What is the Case Study Method?
an in-depth evaluation of single individual. Typically the paticipant in the case study is a psychotherapy client suffering from a problem of interest to the investigator.
What are some problems with case studies?
- generalizing form a single individual to other people. Just because one person reacts to events in a certain way does not mean all people do.
- problem of determining cause and effect relationships with the case study method
- investigators’ subjective judgements can often interfere with scientific objectivity in case study work.
What are some Strengths of the case study method?
- it is valuabe for generating hypotheses about the nature of human personality.
- its useful when examining a rare case
- useful when researchers can argue that the indivual being studied is essentially no different from all normal people on the dimension of interest.
- It’s appropirate to illustrate a treatment and might just be used to demonstrate the possibilities.
What are the 3 most common statistical tests called?
- Analysis of variance (ANOVA - used for continous dependent variables, compare levels of independent variable on dependent variable)
- Chi-square test (used for categorical variables)
- Correlation coefficient (varaibles are measured not manipulated)
What level do psychologists use to see if it is statistically significant?
.05 or 5%
Define: Correlation coefficient
this is the appropriate statistical test when we want to understand the realtionship between two measures. (favorite among personality psychologists)
-All variables measured not manipulated, can be used on large samples of participants, allows predicitve rather than casual statements to be made.
To determine is a tests’ credibility what two things do you need to examine?
Reliability & Validity
Define: reliability
reliability is when a test measures consistently.
What do you do to determine a tests reliability?
- can calculate a test retest reliability coefficient.
- internal consistency
- internal consistency coefficient can be calculated.
Define: validity
refers to the extent to which a test measures what it is designed to measure.
What can you do to determine validity?
- comparing test scores will determine predictive validity.
- hypothetical constructs are also useful.
- they can also determine the tests’ face validity, congruent validity, discriminant validity,a and behavioral validation.
What makes a test have good face validity?
that is, on the face of it, the test appears to be measuring construct.
What is congruent validity?
this is to the extent to which scores from the test correlate with other measures of the same construct.
-if two tests measure the same thing, scores from the two tests should be highly correlated.
What does discriminant validity refer too?
the extent to which a test score does not correlate with the scores of theoretically unrelated measures.
What is behavioral validation?
This is basically making sure that the test scores predict relevant behavior.
