Chapter 5 & 6

Question 1

Sample and sampling

Answer 1

.a subset of participants from a population

.process researcher selects sample of participants in a study

Question 2

Probability sample

Answer 2

the likelihood that any particular individual will be selected for a sample can be specified
.simple random sample is a type of probability sample

Question 3

simple random

Answer 3

every possible sample of the desired size has the same chance of being selected from pop
.every individual has equal chance of selection for sample

Question 4

what’s another way to test assess generalizability of findings without resorting to using a simple random sample?

Answer 4

just by replicating a study on other samples of participants that differ in age/education/socioeconomic status/geographic region/personal or psychological characteristics…

Question 5

Representative sample

Answer 5

.can draw accurate, unbiased estimates of characteristics of the larger population
.can only do this if the sample is REPRESENTATIVE
.still note this is very time consuming and not what is commonly used in psychological research!

Question 6

sampling error

Answer 6

fact that individuals selected for the sample differ from characteristics of the general population

Question 7

error of estimation (margin of error)

Answer 7

the statistical degree to which a sample differs from a population it is from
.ONLY meaningful if what he have is a probability sample, otherwise error of estimation is meaningless

Question 8

Error of estimation is a function of three things:

Answer 8

sample size, population size, variance of data

Question 9

The greater the variability in the data, the more difficult it is to..

Answer 9

estimate the population values accurately. So larger the variance, larger the sample needs to be to draw accurate inferences about the population.

Question 10

systematic sampling

Answer 10

take every nth individual for the sample

Question 11

stratified random sampling

Answer 11

.divide the population first into subgroups or strata (singular stratum)
.like dividing into men and women, or diff age ranges
.then individuals randomly sampled from each strata

Question 12

proportionate sampling method

Answer 12

.cases sampled from each stratum in proportion to their prevalence in the population
.e.g. if we know 55% in city are demos, and 45% are repubs, we would want to make sure our two strata reflect that ration

Question 13

cluster sampling

Answer 13

.researcher first samples groupings or CLUSTERS of participants
.clusters often based on geography or particular institutions (schools)

Question 14

multistage cluster sampling

Answer 14

sample large clusters, then sample smaller clusters from within the large clusters, then sample even smaller clusters until finally obtain sample of participants
.advantages are that we don’t need a sampling frame of the entire population! just a list of institutions or something.
.second, easier to contact participants that share something in common like living area or school

Question 15

nonresponse problem

Answer 15

failure to obtain responses from individuals selected from a sample, or further responses after initially surveyed

Question 16

misgeneralization

Answer 16

researcher generalizes sample results to a population that differs from the one from which the sample was drawn
.think of the landon roosevelt elections

Question 17

nonprobability sample

Answer 17

researchers have no way of knowing the probability that a particular case will be chosen for a sample
.most research uses this

Question 18

convenience sample

Answer 18

includes participants that are readily available (like undergrads!)
.not usually a prob because we’re just looking at relationships between variables and not looking to make a statement about population as a whole

Question 19

quota sample

Answer 19

researcher takes stepes to ensure certain kinds of participants are obtained in particular proportions (like equal amount of men and women)

Question 20

purposive sample

Answer 20

researchers use past research findings or judgment to decide which participants to include in the sample, trying to choose respondents who are typical of the population they want to study.

Question 21

economic sample

Answer 21

one that provides researchers with a reasonably accurate estimate of the population at reasonable effort and cost. Not too large, but just big enough to get a small margin of error!

Question 22

Power

Answer 22

Ability of a research design to detect any effects of the variables being studied that exist in the data.
.particular studies might be powerful enough to detect strong effects but not weak ones, depending on their sample sizes
.larger samples needed when expected effects are weaker

Question 23

Descriptive research

Answer 23

describe characteristics or behaviors of a given population in a systematic and accurate fashion.
.not designed to test hypotheses, but rather provide info about the physical, social, behavioral, economic, or psychological characteristics of some group of people

Question 24

Cross-sectional survey design

Answer 24

A single group of respondents - a “cross-section” of the population - is surveyed.

Question 25

successive independent samples survey design

Answer 25

two or more samples of respondents anser the same questions at different points in time
.e.g. different samples each time. like looking at percentage of americans who say they attended religious services in the past week over decades

Question 26

probs with successive independent samples survey design

Answer 26

samples may change drastically demographically, ethnically, socioeconomically year over year! so can’t always trust conclusions

Question 27

longitudinal or panel survey designq

Answer 27

single group of respondents questioned more than once

Question 28

demographic research

Answer 28

concerned with describing and understanding patterns of basic life events/experiences such as birth/marriage/divorce/employment/migration/death.
.e.g. why people have number of children they do, socioeconomic factors that predict death rates

Question 29

epidemiological research

Answer 29

used to study occurrence of disease/death in different groups of people. psychologists like because can document occurrence of psychological problems like depression, alcoholism, child abuse, shizophrenia, etc, and see if they have any effects

Question 30

simple freq distribution. grouped?

Answer 30

displays number of times each score obtained

groups them from 1-9, 10-19, and so on… can give us relative freq like what percentage scored in each group?

Question 31

diff between histogram and bar graph?

Answer 31

histogram the bars touch each other and the data is continuous (think normal dist or something)
bar graph the data does not touch each other, data ordinal or categorical

Question 32

Confidence interval and error bars

Answer 32

CI, 95% confident successive samples will fall within the CI for example
Error Bars are the I-shaped vertical lines extending from tops of bars in bar graphs.
So 95% samples would fall within the error bars.

Question 33

Positively skewed vs negatively skewed

Answer 33

looks like is approaching the graph if positive (yeah i like this!)
looks like running away if negative (get me outta here!)

Question 34

Z-score

Answer 34

indicates how far from the mean in terms of standard deviations the score falls.
.outliers fall below -3 or above +3
.one std dev above and below captures 68% or responses