Sampling and Statistics (Exam #2 social research methods)

Question 1

systematic sampling error

Answer 1

An error that arises from some basic defect in the sampling or preparation process such that the result obtained is always either higher or lower than the true figure

Question 2

Random sampling

Answer 2

A method of sampling that relies on a random, or chance, selection method so that every element of the sampling frame has a known probability of being selected

Question 3

Random assignment

Answer 3

A procedure by which each experimental subject is placed in a group randomly

Question 4

Probability sampling

Answer 4

Sampling methods that rely on a random, or chance, selection method so that the probability of selection of population elements is known

Question 5

non-probability sampling

Answer 5

Sampling methods in which the probability of selection of population elements is unknown

Question 6

target population

Answer 6

A set of elements larger than or different from the population sampled and to which the researcher would like to generalize study findings

Question 7

sampling frame

Answer 7

A list of all elements or other units containing the elements in a population

Question 8

simple random sampling

Answer 8

A method of sampling in which every sample element is selected purely on the basis of chance through a random process

Question 9

systematic random sampling

Answer 9

A method of sampling in which sample elements are selected from a list or from sequential files, with every nth element being selected after the first element is selected randomly

Question 10

what are the four most common types of probability (random) sampling

Answer 10

simple random sampling, systematic random sampling, cluster sampling, and stratified random sampling

Question 11

stratified random sampling (proportionate vs. disproportionate)

Answer 11

A method of sampling in which sample elements are selected separately from population strata that the researcher identifies in advance
ex) strata is race, income, gender, SES… age

Question 12

Cluster sampling

Answer 12

Sampling in which elements are selected in two or more stages, with the first stage being the random selection of naturally
occurring clusters and the last stage being the random selection of elements within clusters

Question 13

Random assignment is associated with what type of validity?

Answer 13

internal validity

Question 14

Random sampling is associated with what type of validity?

Answer 14

external validity

Question 15

proportionate stratified random sampling

Answer 15

Sampling method in which elements are selected from strata in exact proportion to their representation in the population

pro: eliminates any possibility of sampling error

Question 16

disproportionate stratified random sampling

Answer 16

Sampling in which elements are selected from strata in proportions different from those that appear in the population (the probability of selection
of every case is known but unequal between strata)

Question 17

single-stage cluster sampling

Question 18

multistage cluster sampling

Answer 18

clusters within clusters

Question 19

primary sampling units

Answer 19

Units listed at each stage of a multistage sampling design

Question 20

availability / convenience sampling

Answer 20

Sampling in which elements are selected on the basis of convenience

ex. Popular magazines periodically survey their readers by printing a questionnaire for readers to fill out and mail in.

Question 21

Quota sampling

Answer 21

A nonprobability sampling method in which elements are selected to ensure that the sample represents certain characteristics in proportion to their prevalence in the population
hint: looking at trends

ex. brand perference amongst age groups

Question 22

purposive / judgmental sampling

Answer 22

A nonprobability sampling method in which elements are selected for a purpose, usually because of their unique position

Question 23

three guidelines for selecting informants when designing any purposive sampling strategy. Informants should be:

Answer 23

1. Knowledgeable about the cultural arena, situation, or experience being studied;
2. Willing to talk
3. Representative of the range of points of view

Question 24

random sampling error

Question 25

descriptive statistics

Answer 25

Statistics used to describe the distribution of and relationship among variables

Question 26

inferential statistics

Answer 26

Statistics used to estimate how likely it is that a statistical result based on data from a random sample is representative of the
population from which the sample is assumed to have been selected

Question 27

Mode

Answer 27

The most frequent value in a distribution

Question 28

Mean

Answer 28

The arithmetic, or weighted, average computed by adding the value of all the cases and dividing by the total number of cases

Question 29

Median

Answer 29

The position average, or the point, that divides a distribution in half (the 50th percentile)

Question 30

Variance

Answer 30

A statistic that measures the variability of a distribution as the average squared deviation of each case from the mean

Question 31

standard deviation

Answer 31

The square root of the average squared deviation of each case from the mean

Question 32

Matrix

Answer 32

A chart used to condense qualitative data into simple categories and provide a multidimensional summary that will facilitate subsequent, more intensive analysis

Question 33

internal consistency / inter-item reliability

Answer 33

An approach that calculates reliability based on the correlation between multiple items used to measure a single concept

if items are highly correlated

Question 34

Example of descriptive statistics?

Answer 34

mean, median, mode, standard deviation, range, variance

Question 35

What happens when the sample size increases?

Answer 35

the range will increase/ be larger (more data, more variation) + catch an OUTLIER!!- increases the rang

Question 36

What does Inferential Statistics do?

Answer 36

1. Estimate pop characteristics from sample
2. Test hypotheses about relationships