APA, Ch. 5, 7, 8, 9 Flashcards
A sample from a population is called?
Sampling
Parts of a research paper
Structure-content-citation rules
The ultimate goal of a sample is to?
Generalize (external validity + represent)
Is the accuracy with which the results of an investigation maybe generalized to a different group from that one study
External validity
When an investigator is interested in studying a group of people with particular characteristics of interest, that group is known as a
Population
We might instead select a subset of the population or universe thought to represent the entire group, a subset known as a
Sample
Is the degree to which the samples parameters DIFFER from the parameters of the population from which it was selected
Sampling error
There are two sampling methods
Probability sampling and nonprobability sampling
Is it generally most preferred by researchers. It involves the selection of elements from a population or universe in accordance with some set of mathematical rules, thereby permitting calculation of the probability of sampling error.
Probability sampling
Is the most elementary form of probability sampling. Each element in the population or universe is afforded an equal opportunity of being selected to the sample.
SRS
Simple random sampling
The second variety of probability sampling, like simple random sampling, requires a complete sampling frame, from which every element is selected following a random start
Systematic sampling
Like the previous two techniques, ______ requires the generation of a complete sampling frame. It’s particular advantage, however, is that it permits the researchers some assurance that elements with particular characteristics are included in the sample.
Organizing the elements in the sampling frame into subsets based on some characteristics of interest, or using one of the previous two techniques to select a proportional representation from each subset to the sample.
Stratified sampling
Is a probability sampling technique that is particularly useful when dealing with a very large target population or universe when it would be inconvenient or impossible to generate a complete sampling frame of elements.
The choices of elements are continuously narrowed until a complete sampling frame becomes possible, then the final elements are chosen from the sampling frame in accordance with one of the previous three sampling techniques
MCS
Multistage cluster sampling
While most researchers prefer probability sampling techniques, there are numerous occasions went non-probability must be used
Nonprobability sampling
How can we improve sampling?
We can replicate (different place, different people, different time)
We can use theory or logic to support the claim
Based on mathematical rules
Probability sampling
Uses some form of random selection-requires a complete frame.
Probability sampling
n = sample size,
Systematic sampling
Uses proportional reduction Tatian’s of a certain valuable(Gender, ethnicity, or age)
Males = 60%, females = 40%
Stratified sampling
Separate the population into mutually exclusive sets (strata)
Example = sex-male •female • draw random samples from each stratum by using one of the previous two techniques
Stratified sampling
Useful for a very large target population-when it seems impossible to generate a complete sampling form
Multistage cluster sampling
MCS
Not based on probability (no mathematical rules, not random
Nonprobability sampling
Availability sampling, relies on a available sample
Convenience sampling
Judgmental sampling, selecting sample based on specific characteristics of interest to the researcher.
Example = topic-combination effectiveness in the successful business.
IBM or Microsoft because of success
Purposive sampling
Selecting sample according to some quotas-but not randomly. Represents major characteristics of population (ethnicity, gender) by sampling proportional amount of each.
Quota sampling
Network sampling. One person recommends another, who recommends another, who recommends another. We use when = hard-to-reach populations.
Snowball sampling
Less effort, less time, less resources.
Nonprobability sampling
Limitations? Possible to misrepresent population. Cannot estimate the sampling error, which may cause potential problems in generalizing.
Nonprobability sampling limitations
The gap or difference between the nature of the population
Big circle = population small circle = with in population-sample
Really big population, really small sample = big gap!
If people in population are similar to each other-possible to select any element that represents the population.
Homogeneity
If people are dissimilar - samples must increase in size to reduce the likelyhood of error
Heterogenous
The variables expected to influence a change in another variable
Independent variable
Those expected to change as a result of the actions of the independent variables
Dependent variables
All other variables that might somehow influence the relationship between the independent and Dependant variables, those extraneous to the relationship, are called
intervening variables
While another group receives imposed treatment, and is referred to as the
Control group
In many cases one or more of the groups receives some level of the independent variable, or some treatment, and is referred to as the
Treatment group
We have two groups, each receiving some form of treatment, whether it be lecture or discussion, and those groups are compared with one another, and are therefore known as
Comparison groups
Prior to the imposition of the independent variable, all the groups were equivalent with regard of the dependent variable. This assumption is referred to as
Group equivalence
Participants selected for an investigation are assigned to a treatment, control, or comparison group based on some randomizing technique.
This randomizing technique can be used for the lottery, use of a set of random numbers, or a systematic sampling technique.
Random assignment
Established treatment, control, or comparison groups are evaluated on the dependent variable prior to the introduction of any treatment.
Pretesting
Participants in the treatment, control, or comparison groups are matched on characteristics thought to be important to the D pendant variable.
Matching
All participants in all groups are kept uniform with regard to significant characteristics thought to influence the dependent variable
Constancy matching