Task 5 Flashcards
What is a sample?
A small subgroup chosen from the larger population
What is a sub population?
Because you cannot study eighth graders from everywhere in the world, due to the monetary costs of a study, a “sub population” would be eighth graders from a certain region of the country (city,town or district).
What is the goal of research regarding sampling?
That it results based on a sample of individuals can be applied to the larger population from which the individuals are drawn.
What is generalization?
The ability to apply findings from a sample to a a larger population.
What is external validity?
Something studies possess when their findings can be applied across a variety of research settings and subject populations.
What is the best procedure to draw a sample from a population?
To use a random sample
What is a random sample?
Every person from the population has an equal chance to be selected for the study.(which allows for higher level of generality from research to real life)
What about non random samples?
-They’re used by most psychological research usually from individuals from a highly specialized sub population; like college students (meaning less external validity as you sacrifice the generality of your results)
Does sampling always have to be random?
- most research in psychology doesn’t have specific-to-specific application
- goal of most psychological research is To predict from general levels(theory) to specific (specific Behaviour)
- findings from psychological research are applied indirectly through theory and models
What factors should you consider when acquiring human participants for research?
- The setting in which your research will take place
- Any special needs of your particular research
Screen potential participants for certain characteristics(gender age etc)
-Any institutional,departmental, and ethical policies and guidelines governing the use of participants in research
Comply with the APA Guidelines
Acquiring human participants for research: Factors to consider : What are the two settings where your research could take place?
Laboratory research
Field research
What does laboratory research consist of?
Soliciting volunteers or using a subject pool (required to participate in a certain number of studies, like here in Maastricht)
What does field research consist of?
Selecting participants while they are in their natural environment (selecting participant from a population, contacting a person having them fill a questionnaire)
What is the volunteer bias?
Samples that are made up only by volunteers affect external validity
What are the factors that affect the decision to volunteer?
- the personal characteristics of volunteers (shared)
- situational factors
What are some situational factors that might increase the want for volunteering?
- Incentives to participate
- Personal characteristics of recruiter
- Amount of stress present in experiment
- The degree to which participants feel volunteering is normative
How does volunteerism relate to internal validity?
Volunteerism affects “inferred causality” which restes to internal validity
What is internal validity?
Refers to the confidence we place in the cause and effect relationship in research.
What does it mean that there is high internal validity?
We are better able to argue that the relationship is causal, whereas in studies with low internal validity causality cannot beinferred at all.
How is volunteerism related to external validity?
Volunteerism may affect our ability to generalize, thus reducing external validity
Some remedies for volunteerism?
Fck you man
What are three sampling related issues to consider when making samples from a population?
- Representativeness
- Sample technique
- Sample Size
What is a representative sample?
One that closely matches the characteristics of the population
How is a non representative sample called?
Biased sample
Representativeness: What are some ways to reduce the biased sample?
- Make an effort to determine whether it includes members from all segments of that population in which you have an interest
- to overcome biased sample lists use multiple lists
Sampling technique: Types of sampling : What is simple random sampling?
-Randomly select a certain number of individuals from the population
How is simple random sampling carried?
— statistical tests are conducted to ensure that chosen participants have really been chosen at random
— Closing your eyes and ripping your finger at random number table
—- a variant of random sampling; random digit dialing (when conducting telephone survey)
—-Select a larger sample; more likely to represent all segments of a population
What is the systematic bias?
Bias resulting from the system, leading in average to systematic errors(measured values systematically too high or low), in contrast to random errors, which in contrast cancel each other out.
What are the different types of sampling?
Simple random sampling
Stratified sampling
Proportionate sampling
Systematic sampling
Cluster sampling
Multistage sampling