SS Research Methods Exam #2
A researcher is examining motor skills development by observing children at 18 months, 24 months, and 30 months. If the researcher uses a cross-sectional design and obtains 20 scores for each age, then how many children participated in the entire study?
60
Time-Related Variables
Any variable that changes over time and influences the participants differently in one treatment that in another.
Participant-Related Threats for Designs That Compare Different Groups
Assignment Bias
The basic treat to internal validity for nonequivalent groups design is
Assignment bias
A research study records a score measuring alcohol use and a score measuring income level for each individual in a group of 40-year-old men. The study intends to determine whether there is a relationship between the 2 variables. This study is an example of what research strategy?
Correlational
A study examining what percentage of married couples is satisfied with their marriage is an example of what research approach?
Descriptive
This design - uses participant characteristics such as gender, race, or personality to assign participant groups - no random assignment - dependent variable is measured for each participant to obtain a score within groups - classified as non experimental research design
Differential Research Design
Which of the following is not a disadvantage of a between-subject design?
Each score is independent of all other scores
General Threats for All Designs
Environmental Variables
Single Blind and Double-blind studies minimize this
Experimenter Bias
Counterbalancing
For within-subjects design, this is defined as chaining the order in which treatment conditions are administered from one participant to another so that the treatment conditions are matched with respect to time.
In between-subjects experiments, participants are assigned to treatments using random assignment. Why is random assignment used?
It is an attempt to control participant variables so they don't become confounding variables
This is a threat to internal validity because observed differences between treatment conditions may be caused by this instead of by the treatments
Maturation
Which of the following differentiates a matched-subjects design form a within-subjects design?
The matched-subjects design uses a different group of participants for each treatment condition.
Which of the following accurately describes nonequivalent group design?
The researcher cannot control which people go into each group and cannot ensure that the groups are equivalent
Threat for Designs that Compare One Group Over Time
Time-Related Variables
The goal of the experimental research strategy is to establish the existence of
a cause-and-effect relationship between two variables
A researcher systematically varies the people's stress levels to examine the effects of stress on performance. The researcher includes a measure of stress as
a manipulation check
The appropriate hypothesis test for a within-subjects design that compares two treatment conditions is
a repeated-masures t-test
Internal Validity
a research methods has this if it produces a single, unambiguous explanation for the relationship between to variables
nonequivalent group design
a research study in which the different groups of participants are formed under circumstances that do not permit the researcher to control the assignment of individuals to groups, and the groups of participants are considered nonequivalent.
Differential Research Design
a research study that simply compares preexisting groups.
Treatment Condition
a situation or environment characterized by one specific value of the manipulated variable.
Which of the following is not an example of a non experimental or quasi-experimental study?
a study comparing performance in a room where the walls have been painted yellow versus performance in a room painted blue
History
a threat to internal validity because any differences that are obsessed between treatment conditions may be caused by this instead of by the treatment
A researcher evaluates the effectiveness of an art class having an art expert judge the quality of student's paintings at the beginning of the class, in the middle of the class, and at the end of the class. If the art expert's standards for judgment change during the class, then the internal validity of the study is threatened by
a time-related variable
In a posttest-only nonequivalent control group design one group is observed/measured ____(before, after, same time) receiving a treatment, and the other group is measured _____ (before, after, same time) but receives no treatment
after, at the same time
Extraneous variables
all variables in the study other than the independent and dependent variables
Resentful demoralization occurs when
an untreated group learns of the treatment recede by another group and then becomes less motivated
Instrumentation is a threat to internal validity because
any observed differences between treatment conditions may be caused by changes in this instead of the treatments
Order effects threaten internal validity because
any observed differences between treatment conditions may be caused by order effects rather than the treatments
Cohorts
are individuals who were born at roughly the same time and grew up under similar circumstances
Individual differences
are personal characteristics that can differ from one participant to another
Developmental Research Designs
are used to examine changes in behavior related to age
Experiment/ true experiment
attempts to show the changes in one variable are directly responsible for changes in a second variable
Regression Toward the Mean/ Statistical Regression is a threat to internal validity because
changes that occur in participants' scores from one treatment to the next can be caused by ____ instead of the treatments
Individual difference are
characteristics of the environment that differ between groups
When the data do not consist of numerical scores it is impossible to examine mean differences between groups. In this situation, which statistical analysis is most appropriate for a between-subjects design?
chi-square test for independence
The primary problem with a cross-sectional developmental design is that differences between age groups may not be caused by age but rather are caused by
cohort effects
A researchers designs a study to determine whether female preschoolers prefer sweetened or unsweetened cereal. The researcher uses a box of sweetened colorful cereal and a box of unsweetened tan-colored cereal. The research finds that the group preschoolers ate more of the sweetened colorful cereal and therefore prefers the sweetened cereal. Which 2 variables are confounded in this experiment?
color of the cereal and sweetness of the cereal
posttest-only nonequivalent control group design
compares 2 non-equivalent groups of participants.
pretest-postest nonequivalent control group design
compares two non-equivalent groups and is considered quasi-experiemtnal because it limits threat to internal validity
manipulation
consists of identifying the specific values of the independent variable to be examined ant then creating a set of treatment conditions corresponding to the set of identified values
In an experiment, the score for each participant is obtained by measuring the
dependent
Which of the following is not a risk when participants in one group have an opportunity to talk with participants in the other groups in a between-subjects experiment?
differential attrition
Counterbalancing eliminates confounding by
disrupting any systematic relationship between the order of treatments and time-related factors
matched-subjects design
each individual in one group is matched with a participant in each of the other groups. This is done so that the matched individuals are equivalent w/ respect to a variable that the researcher considers to be relevant to the study.
In between-subjects design
each participant experiences only one level of the independent variable
Experimental research strategy
establishes the existence of a cause-and-effect relationship between two variable. To accomplish this goal, and experiment manipulates one variable while a second variable is measured and other variables are controlled.
longitudinal developmental research design
examines developmental by observing or measuring a group of cohorts over time
Manipulating an independent variable involves
exposing participants to at least two levels of the independent variable
If a researcher measures self-esteem with the Rosenberg Self-Esteem Scale, will other researcher get the same results measuring self-esteem with the Harter Self Esteem Measure This is a question of...
external validity
Results from a research study suggest that a stop-smoking program is very successful. However, the participants who volunteered for the study were all highly motivated to quit smoking and the researcher is concerned that the same results may not be obtained for smokers who are not as motivated. This study has a problem with
external validity
time-series design
has a series of observations for each participant before a treatment or event and a series of observations after the treatment is over
When an outside even occurs during a wishing-subject study and influences some of the treatment conditions but not others, the results are confounded by ____
history effects
An extraneous variable can be eliminated completely by
holding it constant
In a time series design, the series of observations before treatment helps reduce threats to internal validity because
if an outside factor is influencing the scores, the effects should be seen before the treatment is administered.
What is the advantage of a field study over a laboratory study?
increased external validity
What is the advantage of a laboratory study over a field study?
increased internal validity
What is the appropriate statistical analysis for comparing mean differences for a differential design comparing samples representing three populations?
independent-measures analysis of variance
In a within-subjects design, individual differences (participant variables) are a problem because
individual differences are not a problem in a within-subjects design.
A researcher evaluates the effectiveness of an art class by having an art expert judge the quality of student's paintings at the beginning of the class, in the middle of the class, and at the end of the class. If the art experts standards for judgment change during the class, then the internal validity of the study is threatened by
instrumentation
A research study finds that a group of participants who received relaxation training had lower exam anxiety scores than a group who did not receive training. However, the researcher suspects that the difference between groups may be caused by the fact that the participants in one group are generally smarter than those in the other. This study has a problem with
internal validity
In a between-subjects experiment, assignment bias is a threat to
internal validity
In a between-subjects experiment, when the participants in one group have characteristics that are noticeably different form those in another group the _____ of the study is threatened.
internal validity
Non experimental research strategy & Quasi-experiemental research strategy
involved comparison of scores from different groups or conditions. But these strategies use a non manipulated variable to define the groups or conditions being compared
Matching
involves assigning individuals to groups so that a specific variable is balanced, or matched, across the groups. The intent is to create groups that are equivalent ( or nearly equivalent)
No-treatment Control Group
is a condition in which participants do not receive the treatment being evaluated
Placebo Control Group
is a condition in which participants receive a placebo instead of the actual treatment
Research strategy
is a general approach to research determined by the kind of question that the research study hopes to answer
Research design
is a general plan for implementing a research strategy. Specifies whether the study will involve groups or individual participants, will make comparisons within a group or between groups, and how man variables will be included.
treatment
is a manipulation administered by the researcher
Statistical Regression or regression toward the mean
is a mathematical phenomenon in which extreme scores (high or low) on one measurement tend to be less extreme on a second measurement
pre-post design
is a research study in which a series of observation is made over time for one group of participants
Manipulation Check
is an additional measure to assess how the participants perceived and interpreted the manipulation and/or to asses the direct effect of the manipulation
Research Procedure
is an exact, step-by-step description of a specific research study
Confounding Variable
is an extraneous variable (usually unmonitored) that changes systematically along with the two variables being studied. Provides an alternative explanation for the observed relationship between two variables, and is a threat to internal validity
event
is an outside occurrence that is not controlled or manipulated by the researcher
Threat to external validity
is any characteristic of a study that limits the ability to generalize the results from a research study
Threat to internal validity
is any factor that allows for an alternative explanation
Extraneous Variable
is any variable in a research study other than the specific variables being studied
simulation
is the creation of conditions within an experiment that simulate or closely duplicate the natural environment in which the behaviors being examined would normally occur
Random Assignment
is the use of a random process to assign participants to treatment conditions
Randomization
is the use of a random process to help avoid a systematic relationship between two variables
Goal of Counterbalancing
is to use every possible order of treatments w/ and equal number of individuals participating in each sequence.
Non manipulated varaible
is usually a participant characteristic or a time variable.
And advantage of a multiple-treatment within-subjects design compared to a two- treatment design is
it is more likely to reveal the full relationship between the independent variable and the dependent variable
In a between-subjects design, large individual differences can lead to
large variance within treatments
A within-subjects design has a definite advantage over a between-subjects design when the number of available subjects is relative ___ and individual differences are relatively ___ (large? small?)
large, small
A quasi-experimental design
makes some attempts to minimize threats to validity
Which two elements of a research study are unique to experimental research?
manipulation and control
For an experiment comparing 2 treatments, the researcher selects participants so that each treatment condition has 20 males and 10 female. For this study, what method is being used to control participant gender?
matching
An advantage of matching a variable across treatments rather than using random assignment to form your groups is that
matching guarantees that there is no systematic relationship between participant characteristics and the treatment conditions
Which of the following is the primary goal for randomizing and extraneous variable in an experiment?
minimize the likelihood that the variable is confounding
Standardizing procedures within each treatment condition
minimizes variance within treatments
A researcher can't use random assignment to create groups of participants for what research design?
nonequivalent group design
A research study begins by separating a sample 40-year-old men into two groups: a high-income group and low-income group. A score measuring alcohol use is then obtained for each man. The study intends to determine whether there is a relationship between income and alcohol use. This is an example of what research strategy?
nonexperimental
Differential research is classified as
nonexperimental
Carry-over effects
occur when one treatment condition produces a change in the participants that affects their scores in subsequent treatment conditions.
Order effects
occurs when the experience of being tested in one treatment condition (participating and being measured) has an influence on the participants' scores in a later treatment condition(s).
Experimenter Bias
occurs when the experimenter's expectations or personal beliefs regarding the outcome of the study influence the findings of a study.
Assignment bias
occurs when the process used to assign different participants to different treatments produces groups of individuals with noticeably different characteristics
In the non experimental pretest-posttest design, each individual in a single group of participants is measured...
once before treatment and once after treatment
In a pretest-postest nonequivalent control group design on group is measured ____ (one, twice), before and after a treatment is given. And the other group is measured at the same time ____ (once, twice) but does not receive any treatment
once, twice.
A researcher is conducting an experiment comparing 3 treatment conditions. If the researcher uses a between-subjects design. there will be ____ score(s) for each participant but if a within-subjects design is used there will be ____ score(s) for each participant.
one and three
In a typical pre-post study
one group is measured before and after a treatment
The single-factor two group design includes
only two levels of one independent variable
An experiment includes a treatment condition, a no treatment control, and a placebo control. Which two conditions should be compared to determine the size of the placebo effect?
placebo vs. no-treatment
Common examples of progressive error are
practice effects and fatigue
A disadvantage of the two-group design is that it
provides limited information about the effect of the independent variable
What name is given to the variable that is used to define the groups or conditions in a quasi-experiemntal study?
quasi-independent
Which of the following is not a method for trying to prevent a participant characteristic (such as age or gender) from becoming a confounding variable in between-subjects experiment?
randomly select the participants form the population
A no-treatment control group is a condition in which participants
receive a zero-value of the independent variable
Cohort effects and generation effects
refer to differences between age groups (or cohorts) caused by unique characteristics or experiences other than age.
Placebo Effect
refers to a response by a participant to an inert medication that has no real effect not the body. Effect occurs simply because the individual thinks the medication is effective
Progressive error
refers to changes in a participant's behavior or performance that are related to general experience in a research study but not related to specific treatment(s).
Instrumentation
refers to changes in the measuring instrument that occur during a research study in which participants are measured in a series of treatment conditions
External validity
refers to the extent to which we can generalize the results of a research study to people, settings, times, measures, and characteristics other than those used in that study.
Control group
refers to the non-treatment condition in an experiment
Experimental group
refers to the treatment condition in an experiment
What is the appropriate statistical analysis for evaluating the before treatment versus after treatment mean difference for a pretest-posttest design?
repeated-measrues t test
Between-Subjects Experimental Design or Independent Measures
requires a separate, independent group of individuals for each treatment condition. As a result, the data for this design contains only one score for each experiment.
Field Study
research conducted in a place that the participant or subject perceives as a natural environment
How many groups of participants would be needed to completely counterbalance a within-subjects experiment with 3 treatment conditions
six
In a between-subjects design, you can increase the likelihood of finding a difference between the treatment conditions by
taking steps to minimize variance within groups
Levels
the different values of the independent variable selected to create and define the treatment conditions
A researcher has observed that people who suffer form an eating disorder tend to have lower self-esteem than people without a disorder. However, the researcher is not sure whether the lower self-esteem leads to an eating disorder or whether having an eating disorder leads to lower self-esteem. This is an example of
the directionality problem
Restricted Random Assignment
the group assignment process is limited to ensure predetermined characteristics (such as equal size) for the separate groups
One of the primary advantages of a pretest-poshest nonequivalent control group design, in comparison to other nonequivalent group designs is
the presets scores can help reduce the threat of assignment bias
Diffusion refers to
the spreading of treatment effect from the experimental to the control group
Independent Variable
the variable manipulated by the researcher. Usually consists of two or more treatment conditions to which participants are exposed.
Dependent variable
the variable that is measured to obtain the scores within each group in non experimental and quasi-experimental groups
Dependent Variable
the variable that is observed for changes to asses the effects of manipulating the independent variable
Quasi-independent variable
the variable that is used to differentiate the groups of participants or groups of scores being compared in non experimental and quasi-experimental research designs
Quasi experimental designs are different from non experimental because?
this designs actively attempts to limit threats to internal validity
Non Experimental are different from Quasi- experimental designs because?
this designs make little or no attempt to control threats to internal validity
The internal validity of the pre-post designs is threatened by
threats related to time
A prison psychologist measures depression for a group of prisoners each day for one week before and for one week after the psychologist begins a series of group therapy sessions. This is an example of a(n) ____design
time series
The goal of differential research design
to determine whether the scores for one group are consistently different form the scores of another group
What is the general purpose for using simulations and field studies?
to increase external validity
If a researcher has a reason to expect large and long-lasting order effects, the best strategy is
to use a between-subjects research design
Cross-sectional development research design
uses different groups of individuals, each group representing a different age. The different groups are measured at one point in time and then compared
nonequivalent control group design
uses preexisting groups, one of which serves in the treatment condition and the other in the control condition. Researcher doesn't use random assignment.
History effect
when a group of individuals is being tested in a series of treatment conditions, any outside event(s) that influences the participants' scores in one treatment differently than in another treatment.
Maturation
when a group of individuals is being tested in a series of treatment conditions, any psychological or physiological changes that occur in participants during the study and influences the participants' scores.
Counterbalancing is used in
within-subjects designs to reduce individual differences