Neuro 9 (Studies)

Variable

Attribute that can take different values

Independent variable

Variable influenced by experimenter

Dependent variable

Variable that is being tested to see if independent has an effect

Qualitative data

Information in verbal or narrative form

Quantitative data

Information given in numerical form

Sample

A limited number of observations from a set with attributes relevant to the research question

Population

The entire set

Negative correlation

When one variable increases the other decreases

Positive correlation

Increase in one variable is associated with an increase in another variable

Mean

Measure of central tendency (average)

Median

The value that divides a distribution in two (the 50th percentile)

Mode

The most frequently occurring value

Normal distribution

Distribution that is unimodal and symmetrical around its mean (bell curve)

Hypothesis testing

Use statistical inference to test if variables are related

Null hypothesis

States that the variables in question are not related

Snowballing sampling

Subjects tend to recruit their friends

Correlational study

Study designed to see if two or more variables are related; does not give cause and effect

Case study

Study that investigates a single person or a small group

Ethnography

Holistic study on the culture of a group of people

Observational study

Study that uses a sample to draw conclusions about a population; researcher does not control an independent variable or manipulate the environment

Case-control study

Study that compares a group of people with a particular outcome against a group of people who do not have that outcome

Cross-sectional study

Study that draws from a population at a single point in time

Longitudinal study

Study that gathers the same data from a set of individuals at many points in time

Experimental study

Researchers actually manipulate the groups or environment study; establish cause and effect

Randomized controlled trial

Experimental medical study where patients are randomly assigned to receive different treatments

Prospective study

The outcome of interest lies in the future

Retrospective study

The outcome of interest has already happened

Mixed-methods study

Study that uses quantitative and qualitative data

Hawthorne effect

A change in the behavior of study subjects in response to their knowledge of being observed (observer bias)

Operationalization

The process of establishing parameters designed for indirect measurement of a phenomenon that may not be readily directly measurable

Operational definitions

Clear definitions of terms in a process or procedure to be used in acquiring data on the properties of a phenomenon, group, or object

Survey-response bias

Tendency for respondents to written or oral survey to offer false, dishonest, or misleading answers

Reliability

Measure is reliable if the same result can be obtained over repeated measurements

Validity

Measure is valid if it actually measures what it purports to measure

External validity

General applicability of a study's results to other similar situations

Internal validity

Validity of a given study's evidence toward supporting its conclusion

Quantitative methods

Focus on producing data in numbers for use in statistical tests

Qualitative methods

Methods focusing on producing textual descriptions

Ethnographic methods

Participatory field research and informant interviews

Survey methods

Uses a questionnaire