Scientific Research & Statistics

qualitative research / quantitative research

methods of scientific research < (2)

quantitative research

has individual variables, correlational methods, and experimental & non-experimental

individual variables

variables that describe as they exist naturally

correlational method

method that has no cause & effect

correlational method

can measure 2+ variables for each individual

experimental research

has cause & effects

experimental research

has IV/DV and CG/EG

independent variable

variable in experimental research: the cause and/or manipulated

dependent variable

variable in experimental research: the effect and/or the measured

control group (CG)

group in experimental research that has no treatment

experimental group (EG)

group in experimental research that has treatment

random selection

everyone in the population has equal chance of participating

random assignment

technique to control variables: participants are assigned to different groups, basis of chance

descriptive research

measuring one or more separate variables for each individual with the intent of simply describing the individual variables

descriptive research strategy

descriptive research AKA

graph

consistent patterns in the data are often easier to see if the scores are presented this way

scatter plot

type of graph that has each individual being represented by a point

correlational method

research study that simply measures 2 diff variables for each individual

correlational research strategies

correlational method AKA

correlation

the relationship between 2 variables that is ususally measured and described using a statistic

chi-square test

relationship between categorical values is usually evaluatied using this statistical technique

correlational method

this method does not provide an explanation for the relationship

manipulation / control

2 characteristics that differentiate experiments from other types:

manipulation

experimental researcher manipulates one variable by changing its value from one level to another

control

experimental researcher has to ______ all the variables to make sure theres no other causes

environmental variable / participant variable

2 general categories of variables a researcher must consider:

environmental variable

characteristics of a variable such as lighting, time of day, weather conditions, temperature, place, etc.

participant variable

characteristics of a variable such as age, gender, motivation, and personality that vary from one individual to another

individual differences

individuals who participate in research studies will be different on a wide variety of participant variables. Part of every research study

random assignment / matching / holding them constant

3 basic techniques to control other variables

matching

technique to control variables: ensure groups are equivalent in terms of participant variables and environmental variables

control conditions

demonstrate that the treatment has an effect by showing that the scores in treatment condition are substantially different from the scores in no-treatment condition

control condition

no-treatment condition AKA

experimental condition

treatment condition AKA

placebo treatment

neutral treatment

nonequivalent groups study

involves comparing 2 grps of scores, but researcher has no ability to control which participant go into which grp

nonequivalent groups study

comparing preexisting groups, researcher cannot control assignment of participants and cannot ensure equivalent groups

pre-post study

uses passage of time to create the groups of scores

pre-post study

measure same variable twice for each participant, before and after treatment. But researcher has no control over passage of time and other variables that change with time

quasi-independent variable

independent variable in nonexperimental study

quasi-independent variable

in nonexperimental study, this is used to create the diff grps of scores