Unit 0: Sample-Double Blind

sample

the group that the researcher actually studies

population

the group the researcher wants to know about

random selection

process of choosing a sample that guarantees every member of a population has an equal chance of being picked to participate, results in random sample

representative sample

a sample that matches the larger population in terms of ethnicity, gender, race, etc; found using random selection

sampling bias

when a sample does not represent the overall population, giving an unreliable result

convenience sample

when a researcher picks participants based on ease of accessibility to finding them (ex. surveying only people that live in your neighborhood)

survey

obtaining self-reported attitudes and behaviors by asking questions

social desirability bias

poeple lie to look good when asked things about themselves or their beliefs

self report bias

people may misreport their own behavior, thoughts or feelings, perhaps they don’t know or don’t remember the accurate answer

framing

how you frame the question can impact others answers (ex. Are you in favor of socialized medicine or free healthcare for all?)

naturalistic behaviors

research conducted in the natural setting of animals or humans; no interaction is done with the subjects

case study

study one person/group in depth in hopes to reveal things true of us all (ex. Phineas Cage). Disadvantage is that you may not be able to generalize to a larger population

correlational study

measures the relationship btwn two variables WITHOUT manipulating a variable

correlation

measures the relationship btwn two variables CORRELATION DOES NOT SHOW CAUSATION

positive correlation

both variables increase or decrease together

negative correlation

as one variable increases, the other decreases

illusory correlations

the perception of a relationship btwn variables where none exists

3rd variable problem

a 3rd factor that can be the real relationship (ex. heat and shark attacks)

directionality problem

it can be difficult to know which variable is the cause and which is the effect in a correlational study (ex. stress and mental health)

experiment

a research method in which an investigator manipulates one or more factors (IV) to observe/measure the effect on some behavior or mental process (DV). Seeks to identify cause and effect relationships. Disadvantage is that it can be hard to generalize to the real world.

experimental condition/group

exposes a participant to treatment

control condition/group

contrast to the experimental conditions; acts as comparison because participant does not receive treatment or receives a placebo

random assignment

(only used in experimental method) the process in which subjects are placed into an experimental or control group without bias

placebo effect

results causes by expectations alone; you think that you will experience an effect, therefore you perceive that there is an effect

single blind

only researchers (not participants) know who is in the placebo and treatment group

double blind

participants and research staff are ignorant about the treatment/placebo given to each subjects, used so researchers’ expectations can’t influence results