Chapter 1 Section 3: Process Of A Statistical Study Flashcards
Observational study
Observes data that already exists.
Experiment
Generates data to help identify cause and effect relationships.
Representative sample
Has the same relevant characteristics as the population and does not favor one group from the population over another.
Random sampling
Every sample from the population has an equal chance of being chosen
Stratified sampling
Members of the population are divided into two or more subgroups (strata) and a random sample from each stratum is drawn.
Cluster sampling
Divided into clusters, and random samples from some of the clusters are sampled.
Systematic sampling
One chosen by selecting every nth member of a population.
Convenience sample
Sample which is convenient to collect for researcher–nonrepresentational of the population.
Cross-sectional study
Data are collected at a single point in time
Longitudinal study
Data are gathered by following a particular group over a period of time.
Case study
Looks at multiple variables that affect a single event.
Treatment
Is some condition that is applied to a group of subjects in an experiment
Subjects
People or things being studied in an experiment.
Participants
People being studied in an experiment.
Response variable
The variable in an experiment that responds to the treatment
Explanatory variable
The variable in an experiment that causes the changer in the response variable.
Control group
A group of subjects to which no treatment is applied in an experiment.
Treatment group
A group of subjects to which researchers apply a treatment in an experiment.
Confounding variables
Factors other than the treatment that cause an effect on the subjects of an experiment.
Placebo effect
A response to the power of suggestion, rather than the treatment itself by participants of an experiment.
Placebo
A substance that appears identical to the actual treatment but contains no intrinsic beneficial elements.
Single-blind
In this experiment, subjects of not know if they are in the control group or the treatment group, but the people interacting with the subjects in the experiment know in which group each subject has been placed.
Double-blind
In this experiment, neither the subjects nor the people interacting with the subjects know to which group each subject belongs.
Institutional Review Board
A group of people who review the design of a study to make sure that it is appropriate and that no unnecessary harm will come to the subjects involved.
Informed consent
Involves completely disclosing to participants the goals and procedures involved in a study and obtaining their agreement to participate.
Bias
Is favoring of a certain outcome in a study.
Sampling bias
Occurs when the sample chosen does not accurately represent the population being studied.
Dropouts
Are participants who begin the study but fail to complete it.
Processing errors
Errors that occur simply from the data being processed, such as typos when data are being entered.
Nonadherents
Participants who remain in the study until the end but stray from the instructions that they were given.
Researcher bias
Occurs when a researcher influences the results of study
Response bias
Occurs when a researchers behavior causes a participant to alter his or her response or when a participant gives an inaccurate response.
Participant bias
Occurs when there is a problem with either the participation–or lack thereof–of those chosen for the study.
Nonresponse bias
Occurs when there is a lack of participation in a self-selected sample from certain segment s of a populations, when a person refuses to participate in a survey, or when a respondent omits questions when answering a survey.
Meta analysis
Study that compiles information from previous studies
Principles of experimental design
Randomization, control, and replication
