define nominal
measurement that has a clear number; categorical/qualitative data
nominal examples
eye color, ice cream flavors, and nationality.
diff between probability & non-probability sampling
probability sampling: all population members have an equal chance to be selected as long as the population diversity is represented
non-probability sampling: all the populations don't have the same chance to be selected (leaving out ppl)
Probability sampling pros & cons
pros: Good to get a more accurate selection of people that can be applied to the real world.
cons: Might not be as readily available and harder for short time research
Non-probability sampling pros & cons
Pro: Easier to collect samples when don't have the necessary resources.
Con: The downside is that the experiment's results can’t be applied to the real world.
define construct validity
extent to which scores on measure represent the variable or construct they are intended to
list types of validity
face validity
content validity
criterion validity
discriminant validity
define face validity
extent to which variable measures what it is supposed to measure
define Content Validity
extent to which a test samples the behavior that we are interested in; extent to which a measure covers all aspects of the construct of interest
define Criterion Validity
extent to which the measure is related to the outcome & other variables
define Discriminant Validity
Scores on the measures are not related to other measures that are theoretically different.
define confound
external variables that aren't controlled, decreased validity of results
confound ex
This might be the age when looking at obesity and heart disease
list 4 threats to construct validity
1)Reaction 2) socially desirable 3)demand 4)expectancy
Reaction
how people might react differently when they know they are being used for a study
socially desirable
subjects acting as they feel like is a desirable reaction
demand
When subjects try to make sense of the experiment or get inside knowledge
Expectancy
Researchers may be biased in what they are looking at and what they expect to see
Describe single variable research
used for simple experiments, and generally just want to look and learn more about it
single variable research ex
how accurate are first impressions
define ordinal
ranking order w/ no equal intervals
ordinal ex
movie ratings, order of favorite snacks, rank stuff in order
define reliability
extent of which the scores on a measure are consistent across time & multiple items on the same measure
assess reliability by?
redo experiment & compare results
types of reliability
reliability over time
reliability across items
reliability across researchers
Reliability over time (test-retest reliability)
How well your results should be through a specific time period
Reliability across items (internal consistency)
the extent to which items on a multiple item measure are consistent with each other. (questions should have some sort of connection to each other)
Reliability between researchers (interrater reliability)
How consistent the observers are with their judgments.
define statistical validity
how well your results are accurate and can research a conclusion on
statistical validity ex
standard error, standard deviation, and t-test.
list threats to internal validity (MRS.SMITH)
Maturation Regression of the mean selection of subjects selection by maturation interactions mortality instrumentation testing history
define Maturation
a change over time that may change the results for the simple reason of growing
Maturation ex
a person growing up will probably change answers when they are older or have more experiences.
define Mortality
Possible absence of subjects for whatever reason that can include death or not wanting to finish the study
Mortality ex
experiment takes a long time, so some people are unable to continue the time commitment of the study
define Instrumentation
Change in measuring instrument or the use of instruments that might include proper calibration which can threaten validity
Instrumentation ex
using older data might’ve been collected with different machinery and on different units.
define Regression of the Mean
Only taking the top 10% or bottom 10% to explain your results; the tendency that participants who receive extreme scores when tested, tend to have less extreme scores on subsequent retesting even in the absence of any treatment effects.
Regression of the Mean ex
A person who scores an extreme value is less likely to do so if given the experiment again.
define Selection of subjects
Any bias in selecting and assigning participants to groups that results in systematic differences between the participants in each group
Selection of subjects ex
non-random sample selection, cherrypicking certain people because it’s convenient or for other reasons
define selection by maturation interaction
The treatment and no-treatment groups, although similar at one point, would have grown apart (developed differently) even if no treatment had been administered.
selection by maturation interaction ex
Boys and girls in 4th grade vs in 10th grade will be different.
define testing
When participants are repeatedly tested, changes in test scores may be more due to practice or knowledge about the test procedure gained from earlier experiences rather than any treatment effects
testing ex
someone takes the same math test twice, gets a better score on the 2nd attempt.
define history
Extraneous events occurring during the course of the experiment that may affect the participants’ responses on the dependent measure.
history ex
social upheaval may cause change in attitudes or behaviors in people.
Describe cross-sectional research
comparing two pre-existing groups of subjects subjects to specific variables but do not alter such subjects. in medical research exposing subjects to diseases would be highly unethical Instead...take subjects that may already have the characteristics they are looking for and compare them
cross-sectional research ex
-In medical research exposing subjects to diseases would be highly unethical. -Instead take subjects that may already have the characteristics they are looking for and compare them
define survey research
done by sending out questionnaires and relying on individuals to self-report their answers.
survey research characteristics
-relies a lot on the honesty of the individuals. -survey design is essential because it can affect the results.
define interval measurement
meaning, there is order, and the difference between two values is meaningful because there are equal intervals between each score, but there is no true zero
interval measurement ex
temperature, pH, likert scale
Explain correlational research
does not involve the manipulation of variables.
distinguishes correlation research from experimental research
It uses existing data or survey data that is collected. It is easier to do than experimental research and relies highly on participants' honesty. Correlation research does not measure causation, whereas experimental research can test for causation.
Explain what internal validity is
degree to which the changes in the dependent variable are due to the manipulation of the independent variable, and not by something else.
explain why experiments are considered to be high in internal validity.
how much you can say that your results are due to your manipulations and not any other outside factors.
explain context effect
how the surrounding things affect how one might answer
context effect ex
include a survey with answers that look more off than others, and also the order of questions in the survey can impact how people answer
list ex nonexperimental research
correlational research, archival research, single variable, etc.
distinguish nonexperimental research from experimental research, and give several examples.
There is no manipulation of variables, which makes it different from experimental research.
Explain what a psychological construct
tool used to facilitate understanding of human behavior; observable complex traits, behavioral & internal processes w/ multiple operational definitions;
psychological construct ex
intelligence, self-esteem, and depression
define ratio measurement
includes name, natural order, equal intervals, and a true zero
ratio measurement ex
height, the kelvin scale, and enzyme activity.
strengths and weaknesses of qualitative research in psychology compared with quantitative research?
Qualitative research brings a deeper understanding than just quantitative data such as numbers. The numbers bring the data to the experiment, and it might be easier to conclude with the numbers.
manipulation of the independent variable & importance
involves the researcher changing that variable and viewing how the dependent variable changes in response to it. -important to see if there is any causation when changing the independent variable related to the dependent variable
manipulation of extraneous variables & importance
ensures that the trend that the researchers are observing is only due to the manipulation of the independent variable, and not by any outside influence. -increases validity.
Explain external validity
extent our results can be applied or generalized to the real world
two external validity types
Type 1: Ecological -generalizability of the results from one setting to another Type 2: Population -the ability to generalize from your sample to the population of interest
Explain when a researcher might choose to conduct nonexperimental research instead of experimental research
When choosing a nonexperimental, time, money, and resources are all factors
list types of observations
1)Naturalistic Observation 2)Participant Observation 3)Structured Observation
Naturalistic Observation
observing behaviors in the environment in which they occur.
Participant Observation
researchers observe behaviors in the environments in which they occur, but researchers are active participants in the situation.
Structured Observation
gathering quantitative data on a set of predetermined behaviors Ex: how many times do bowlers laugh or make an angry face after bowling?