research methods exam 3 review

what is the research strategy?

refers to the general approach and goals of a research study

• selection of a research strategy is determined by

  • question you plan to address

  • what you hope to accomplish (hypothesis)

what is the research design?

general plan for implementing the research strategy

• require decisions about 3 basic aspects of the research study

  • group vs individual

  • same individuals vs different individuals

  • the number of variable to be included

• provide a general framework for conducting studies

what is internal validity?

concerned with factors in the research study that raise doubts or questions about the interpretation of the results

good internal validity produces a single, unambiguous explanation for the relationship between two variables

random assignment sampling boosts internal validity

threat to internal validity:

• any confounding factor that allows an alternative explanation for the results

what is external validity?

the extent to which the results of a research study can be generalized

a threat to external validity:

• any characteristic of a study that limits the ability to generalize the study’s results

what are the threats to external validity?

1. generalizing across participants or subjects

2. generalizing across features of a study

3. generalizing across features of the measures

what are the threats to generalizing across the features of a study?

novelty effects

• behavior changes due to unfamiliar conditions

  • participants perform better or worse on the first try

multiple treatment interference

• fatigue

• practice

experimenter characteristics/bias

what are threats to internal validity?

extraneous variables

• any variables in a research study other than the specific variables being studied

confounding variables are extraneous variables (usually unmonitored)

• provide an alternative explanation for the observed relationship between the 2 variables

• variable must change systematically alongside other variables and affect dv

what are the types of confounding variables?

environmental variables

• general threats for all designs

participant variables

• individual difference

time-related variables

• threats for designs that compare one group over time or at different time-points

when does an extraneous variable become a counfounding variable?

variable must change systematically alongside other variables and affect dv

must only affect some subjects in the study to make the scores incomparable

how to choose between external and internal validity?

goal of any research study is to maximize both internal and external validity

balancing internal and external validity

• there tends to be a trade-off between internal and external validity

• the purpose or goals of a study help you decide which type of validity is more important and which threats must be addressed

what is the goal of experimental research?

to establish the existence of a cause-and-effect relationship between two variables

experiment (true experiment)

• must demonstrate that changes in one variable are directly responsible for causing changes in the second variable

what is the independent variable

variable that is manipulated by the researcher, creates a set of treatment conditions, choose scale of measurement

treatment condition

• situation or environment characterized by one specific value of the manipulated variable

levels

• different values of the independent variable

• selected to create and define the treatment conditions

what is the dependent variable?

variable that is observed for changes to assess the effects of manipulating the independent variable

what are extraneous variables?

all other variables in the study other than the independent and dependent variables

what are field studies?

research conducted in a place that the participant or subjects perceives as a natural environment

researcher does not use a lab environment 

why do we randomly assign subjects

to protect and increase the internal validity of experimental research

what is the third-variable problem?

third-variable problem

• just because two variables are related, does not mean that there must be a direct relationship between the two variables

  • a third (unidentified) variable may be responsible for producing the observed relationship

the directionality problem

• a correlational study does not establish a relationship of cause-and-effect

what is the goal of the correlation research design?

to establish that a relationship exists between variables and to describe the nature of the relationship

• relationships can be described but not explained

• there is no attempt to manipulate, control, or interfere with the variables

what is a scatterplot?

each individual’s score is shown as a single dot with a horizontal coordinate and a vertical coordinate

what is a positive correlation?

each time the x variable increases by one point, the y variable increases in a consistently predictable amount, slopes upward to the right

what is a negative correlation?

each time the x variable increases by one point, the y variable decreases in a consistently predictable amount, slopes downward to the right

how do we determine the strength of a correlation?

correlation coefficient

• measures and describes the relationship between two variables

pearson or spearman test measure the slope of the line

• the numerical value (0.0-1.0) indicates the strength or consistency of the relationship

  • -0.2 to +0.2 - weak to no correlation-1 to -0.8 and +0.8 to 1 are strong correlations

  • depends on overall effects in field of study

what is the goal of descriptive research?

measure a variable or set of variables as they exist naturally

not concerned with relationships between variables

• results help capture interesting, naturally occuring behavior

what is a case study?

in-depth study and detailed description of a single individual (or a very small group)

• may involve an intervention or treatment administered by the researcher

case history

• a case study without any treatment or intervention

what are the 3 techniques for quantifying observations?

frequency method

• counting instances of each specific behavior

duration method

• fixed-time observation

interval method

• dividing observation period into a series of intervals and recording behavior during each interval

what are the 3 types of observation research designs?

naturalistic observation

• no researcher intervention

participant observation

• researcher interacts with participants and becomes one of them

contrived observation

• researcher sets up a situation likely to produce the desired behavior in participants

what are the strengths and weaknesses of each of the 3 observation designs?

naturalistic observation

• strengths

  • behavior observed in the real world

  • useful for nonmanipulated behaviors

  • actual behaviors observed and recorded

• weakness

  • time-consuming

  • potential for observer influence

  • potential for subjective interpretation

participant observation

• strengths

  • when natural observation is impossible

  • get info not accessible otherwise

  • participation gives unique perspective

• weakness

  • time-consuming

  • potential for loss of objectivity

  • increased chance for observer influence

contrived observation

• strengths

  • do not have to wait for a behavior to occur

• weakness

  • less natural

what is the difference between descriptive research when compared to correlation and experimental research?

• does not assess the relationship between variables

• produce a description of individual variables as they exist within a specific group

• describes individual variables instead of the relationship between variables