the state that exists when statements or conclusions about empirical reality are correct, actually measuring exactly what you intend to measure
attempt to define cause-effect relationships, but fail to fully control for all potential confounds
Experimental Research Strategy
A research strategy that attempts to establish the existence of a cause-and-effect relationship between two variables by manipulating one variable while measuring the second variable and controlling all other variables.
Threat To External Validity
any characteristic of a study that limits the ability to generalize the results from a research study (ex: generalization from a same to the general pop, from one research study to the other, from a study to a real world situation)
Threat to Internal Validity
Any factor that allows for an alternative explanation for the results of within a study.
Descriptive Research Strategy
a general approach to research that involves measuring a variable or set of variables as they exist naturally to produce a description of individual variables as they exist within a specific group
measure the relationship between two variables, but doesn't really explain why
aka regression to the mean, extreme scores have the tendency to return to the mean; has to do with the idea that everyone/thing has a true score/innate ability, it's hard to measure because of confounds
the characteristic of an experiment that allows one to draw accurate inferences about the causal relationship between an independent and dependent variable
extent to which we can generalize findings to real-world settings
A threat to internal validity that occurs when participants are exposed to more than one treatment and their responses are affected by an earlier treatment. Examples of testing effects include fatigue and practice. Also known as order effects.
When a group of individuals is and being tested in a series of treatment conditions, any physiological or psycholoical change that occurs in participants during the study and influences the participants scores.
A Student changing level of interest and background knowledge in algebra, during a study on the effects of response card quiz reviews on the next-day quiz performance is a potential_______________ _________________to the investigation and should be monitored.
Threat to Validity
Any component of a research study that introduces questions or raises doubts about the quality of the research process or the accuracy of the research results.
Refers to the changes in the measuring instrument that occur during a research study in which participants are measured in a series of treament conditions. This is a threat to internal validity because any observed difference between treatment conditions may be caused by the changes in the measuring instrument instead of treaments.
A threat to internal validity that occurs when the process used to assign different participants to different treatments produces groups of individuals with noticeably different characteristics.
A threat to internal validity because any differences that are observed between treatment conditions may be caused by history instead of by treatment. This term refers to the enviorment events other than treatment that change over time and may effect the scores in one treatment differently than in another treatment.
A general plan for implementing a research strategy. This specifies whether the study will involve groups or individual participants, will make comparisons withing a group or between groups and how many variables will be included.
-- A variable that confuses the association between the independent and dependent variables and thus needs to be restricted either within the research design or through statistic procedures
Identifying the specific values of independent variable to be examined and then creating a set of treatment conditions corresponding to the set of identified values.
Demonstrating that changes in one variable tend to be accompanied by changes in another variable simply establishes that the two variables are related. The remaining problem is to determine which variable is the cause and which is the effect.
Prevent extraneous variables from becoming confounding variables. It is only a confoudnign variable if it influence DV and it varies systematically with IV
This are the types of what kind of variables?
enviormental, particpant, Time-related
Holding Variable Constant
hold absolutly constant or limit restricted , Keeping the extraneous variable the same, not always practical, limits external validity
each participant has an equal chance of being in any groupd that is being studied ( created equally)
Between Subject Design
experimental design in which different groups of subjects are exposed to the various levels of the independent variable
Within Subject Design
repeated measure design. all go through every treatment. high power. less number of subjects
Between Subject Comparison
within a study, comparing one group of individuals to a different group
An experiment in which an extraneous variable varies systematically with the IV. It makes drawing a cause and effect relation impossible.this may occur if particpants are not equal before the start of the experiment.
Nonrandom Assignment to Groups
Random assignment tends to create equal groups in the long run.
controls for possible influence of temporal relationship between event and response. EX ulcers due to physical or psychological stress of shock in monkeys.
matching participants on a case-by-case basis for each selected extraneous variable, variables to match should be correlated with the DV (literally form pairs, one with extraneous variable the other w/out)
Frequency Distribution Control
A procedure by which experimental and control groups can be made equivalent by selection of combinations of subjects with comparable aggregate characteristics
ensures influential extraneous variables are balanced among experimental conditions
Free Random Assignment
- THE MOST BASIC AND SINGLE MOST IMPORTANT CONTROL PROCEDURE
- can control threats to internal and external validity
- can control for many variables simultaneously
- the only control procedure that can control for unknown factors
example random numbers
A method of controlling for order effects in a repeated measures design by either including all orders of treatment presentation or randomly determining the order for each subject. also preventing Carry-Over Effects.
subjects in an experiment to whom the independent variable is administered
Placebo Control Group
A control group in which the participants are exposed to a fake independent variable, or placebo. The effects are compared to those of the actual independent variable on the experimental group.
No treatment condition
provides baseline measure of normal behavior.
Single Blind Procedure
Experimentor is unaware, research design in which participants don't know whether they are in the experimental or control group
Partial- Blind Procedure
experimenter unaware for portions of the experiment
an experimental procedure in which both the research participants and the research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo. Commonly used in drug-evaluation studies.
variability in Dv scores that is due to factors other than the IV , such as indv differences, measurement differences, and extraneous variation.
Participant is unaware of what the experiment is really about.
Reduces experimenter-participant contact
when untreated subjects learn of the treatment received by others and demand the same treatment or something "equally good". For example the the coal man knowing he is going to loose his job due to a machine proves that he can work harder than the machine thus keeping his job
A threat to internal validity that occurs when an untreated group learns of special treatment given to another group, and becomes less productive and less motivated because they resent the other group''s expected superiority.