Exam 2
A researcher who is examiing the effects of temperture and humidity on the eating behavior of rats uses a factorial experiment comparing three different temperatures (70, 80, and 90 ) and 2 humidity conditions ( low and high ). How many factors are in the experiment ?
2
How many independent variables are there in a 2 x 2x 2 factorial design ?
3
A strength of the longitudinal design is that it:
Avoids cohort effects
Summarizes the principles set forth by the National Commission for the Protection of Human Subjects of Biomedical and Behavioral Research
Belmont Report
You will be paid $15 in cash.
Costs and Economic Considerations
How do we overcome order effects ?
Counterbalancing - switching the order of condition presentation in order to test and control for order effects
How _____ are analyzed
Data
Variables such as the rooms in which an experiment is conducted, the occurrence of nearby construction, and the time of day during which experiments take place can all contribute to:
Environmental confounding
treated equally
Except for the independent variable, the groups of participants should receive exactly the same experiences.
Identify the difference between fraud and plagiarism
Fraud is the explicit effort of a researcher to falsify or misrepresent data. -Plagiarism is the unethical representation of someone else's ideas or words as one's own.
The U.S. Department of Agriculture's requirements for the use of nonhumans in research can be found in the:
Guide for the Care and Use of Laboratory Animals
Correlations can:
Help in predictions Provide hints at causal relationships Help us predict cause after multiple correlations are discovered (ethical considerations)
Terminology Issues
In a lot of quasi-experimental studies, we still have something that resembles an independent variable and a dependent variable, but IV's are called quasi-independent variables and DV's are called quasi-dependent variables
In a study involving deception, which APA Ethical Principles of Psychologists and Code of Conduct principle is most compromised?
Informed consent
Which method involves assigning individuals to groups so that a specific variable is balanced across the groups?
Matched assignment
Which of the following is a limitation of using matching rather than random assignment to form groups in a between-subjects experiment?
Matching requires another measurement procedure.
What is the appropriate analysis for an interval or ratio scale measure in a pretest-posttest nonequivalent groups design?
Mixed-design ANOVA
Developed in response to Nazi atrocities
Nuremburg Code,
In comparison to between-subjects designs, within-subjects designs are more likely to be affected by:
Order effects
More on Order Effects
Order effects can also impact variance within the groups
Which ethical guideline regarding animal research is upheld in the Ethical Principles of Psychologists and Code of Conduct (APA 2002, 2010)?
Psychologists must perform animal surgical procedures under appropriate anesthesia.
If you have any questions about this study, you may contact Professor Brown at [email protected] or 555-555-1212.
Questions and Further Information
How Do We Control for Extraneous Variables Again?
Randomization Restricted random assignment (RRA) (equal groups) Matching RRA (equal variables) Holding constants
What _____ may be used
Research designs
How do We Minimize Variability Issues?
Standardizing procedures and treatments Controlling for individual differences (matching or holding constant) Larger sample sizes Central limit theorem - as our sample size gets larger, our group averages from populations are less varied
A posttest-only nonequivalent control group design may also be called a:
Static group comparison
Why did the Milgram obedience study bring the questionable treatment of human participants to the forefront?
The participants experienced shame and embarrassment for having behaved inhumanely toward others.
Which design is a within-subjects design?
Time-series
Which of the following is not a possible outcome from a two by two factorial design?
Two main effects and an interaction, two main effects and no interaction, no main effect for either factor but an interaction
a non experimental design
makes no attempt to minimize threats to validity
in _______________the group assignment process is limited to ensure predetermined characteristics for the separate groups.
restricted random assignment
Correlations are not often
the product of experimentation and are usually "observational" in nature.
How can variance be reduced in .a between subjects design
use a factorial design adding a participant variable (such as age) as a second factor
research design is a research study that simply compares preexisting groups.
A Differential
A within-subjects design may also be called
A repeated measure design
Correlation DOES NOT EQUAL
CAUSATION this remains the same for strong correlations
Adopted by the World Medical Association
Declaration of Helsinki,
Charla is studying how people respond to small children throwing temper tantrums in public places. She believes that individuals with their own young children may respond differently from those who do not have children, so she includes only individuals who do not have children. What method is Charla using?
Holding constant
In regards to Between subjects design
However, the nature of the designs often have costs associated with them When running these designs, use caution and consider the numerous problems that can emerge
Why is Variability So Important?
In comparison tests, we're examining how likely it is that the two groups are part of the same population or different populations
How Correlations are Represented (cont.)
In correlations, we pair the data points that we collect to look for relationships Scatter plot - a graph that provides a visual representation of the relationship between variables
A nonequivalent groups design is always threatened by:
Individual differences
A simple and unbiased procedure for selecting sequences is to construct a:
Latin square
Kevin has just completed the active treatment group in his experiment and recognizes that his instructions about how a memory task should be completed have caused confusion. Would it be a good idea for Kevin to rewrite the instructions?
No, because the only thing that should vary between the groups is the treatment condition.
What type of design is illustrated by the preceding diagram?
Pretest-posttest nonequivalent control group design
Ethics is the study of:
Proper action
equivalent individuals
The characteristics of the participants in any one group should be as similar as possible to the characteristics of the participants in every other group.
A nonequivalent groups design is characterized by:
The lack of random assignment of subjects
Which research proposal would most likely be classified as a Category I proposal by the IRB?
The motivation for criminal behavior using anonymous mail surveys
There is research indicating that stress can lead to depressed mood. A researcher plans to give participants a stressful task—public speaking—to induce depression.
The no-harm principle is being violated and is a concern.
You may withdraw from the study at any time, without penalty.
Voluntary Participation
Time-series design
a number of observations before an event and after an event
Curvilinear
a relationship that is represented by a predictable curve across the variables
Monotonic
a relationship that is represented by a steady increase (or decrease) of both variables
Linear
a relationship that is represented by a straight line
Correlational research strategy
an attempt to determine the strength of the association between two or more variables
The students talk to each other, figure out what they think is special about the new methods, and create a do-it-yourself treatment based on the experimental treatment.
diffusion
What term best applies to the APA's work in this area?
guidelines
Margie believes that performance on her test of cognitive flexibility will be related to educational attainment, so she limits her participants to individuals who have a high school diploma or GED.
holding constant
What _____ techniques may be used with which research subjects
measurement
Interrupted time-series event
observations of groups done before and after the event occurred
Between-subjects designs
remove the effects of contamination across conditions Practice or experience Fatigue or boredom Contrast reactions or effects Effect of drug A and B example Necessity
Which statements are consistent with the APA guidelines? Check all that apply.
1) Allows researchers to dispense with informed consent under certain specific circumstances 2) Permits psychologists to offer reasonable inducements, including money, for research participation 3) Requires that psychologists inform potential participants of their right to refuse to participate in research and their right to withdraw from the research at any time 4) Requires researchers to take reasonable steps to minimize harm, should it occur Which statements are consistent with the APA guidelines? Check all that apply.
How many separate groups of participants would be needed for a between subjects 2 factor study with 3 levels of factor and four levels of factor B ?
12
Hillary is in a drug experiment where she takes one drug, performs a task, then takes another drug, and performs the same task. Which of the concerns with within subjects designs shouldn't be an issue in Hillary's task?
Contrast effects ?
Correlations cannot:
Control for third variables, Determine directionality (usually) Determine cause
How does holding a variable constant prevent the variable from becoming a confound? Answer
It eliminates the possibility that the variable will be substantially different from one group to another.
Chantelle is studying how teenage mothers interact with their toddlers. She pays them $250 to allow her to tape their interactions for two hours. Why is this approach problematic?
It might put undue pressure on the mothers to participate.
t-test
Monty has two groups, a treatment group and a comparison group, and is collecting interval-level data
Which of the following does not guarantee that a specific participant variable will not become a confounding variable?
Randomizing the variable across treatment
What is one of the seven basic Institutional Review Board (IRB) criteria for studies involving human subjects?
Reasonable Risk in Relation to Benefits
Which actions are considered safeguards for preventing fraud? Check all that apply.
Replication Peer review Possible suspension
What _____ may be used
Research strategies
In adults who are not diagnosed with eating disorders, eating off of a larger dinner plate has been found to increase the amount eaten. A clinical psychologist would like to conduct the study with clients diagnosed with bulimia nervosa—that is, clients who repeatedly binge on large amounts of food and then purge, commonly through vomiting—to see whether the same effect is found.
The no-harm principle is being violated and is a concern.
When a handful of students in the comparison group learn that they are not getting the "real" treatment, they get angry and channel their anger into doing as well as possible on the tests at the end of the intervention.
When a handful of students in the comparison group learn that they are not getting the "real" treatment, they get angry and channel their anger into doing as well as possible on the tests at the end of the intervention.
A researcher wants to examine whether the size of the font of test questions affects scores on a test. The researcher gives 200 undergraduate students a test printed in size 10 font. The following week, these same students receive a test printed in size 14 font. What type of design is this?
Within-subjects
Control
accounting for the effects that could be caused by all confounding (third) variables
Measurement
collection of data that allows you to determine a quantifiable change/difference in variables of interest
Posttest-Only Design
comparing a variable across (a) group(s) that received a manipulation and those that did not (control) Note: if assignment bias is removed, this is an experimental design
Differential Research Design
comparing a variable across preexisting groups Note: the groups have to be categorical
in comparison we exmine how likely it is that the 2 groups are part of the same population or not by
comparing group means and factoring in variability to estimate the chances of those means being part of the same populations
In a differantial research design what term is used indentifying the participant variable that is used to define the groups
quasi independent
How results are _____
reported
Strength
the change in one variable that can be predicted by another variable
this gives us the ability to conduct within-subject analyses without
worrying about order effects
What type of statistical analysis is most appropriate to use with a single-factor, multiple-group design with an interval or ratio level outcome measure?
ANOVA
How Correlations are Represented
In experiments, non-experimental designs, and quasi-experimental designs we compared averages to find differences between the groups
Why Do Bewteen Subjects Cause Problems?
Large sample requirements Statistical reasons (individual differences) Confounding variables 8 AM versus 2 PM groups Variability variance Note: another goal is to have equal assignment into groups, this causes another problem
A cross-sectional developmental design is an example of which general category of research designs
None equivalent group design
What three basic principles regarding the protection of human subjects are identified in the Belmont Report?
Respect, beneficence, and justice
How subjects are _____
Selected
Involved the deliberate withholding of the cure for syphilis, even when a cure became available
Tuskegee
Other Between-Subject Experiment Concerns
Unequal (differential) attrition Effectiveness of highly involved treatment versus control group example Diffusion of effects Shared information Horoscope experiment example Compensatory rivalry Video game performance example Resentful demoralization Therapy groups revisited
Nonexperimental and quasi-experimental designs:
Use nonmanipulated variables to define groups
How do we identify order effects
Variance consistency measurements (you'll cover this in future stats classes)
ANOVA
Vonda's study has one independent variable, reward magnitude, with three levels (low, medium, and high). Her outcome measure is the number of correct answers on a memory test.
When the data from a within-subjects design experiment are on an ordinal scale, a_____________________ can be used to assess treatment effects.
Wilcoxon test
when order effects are
asymmetrical, we're lost
Comparison
collection and use of data that allows you to determine how/where individuals vary across situations and/or levels
Developmental research design
studies focusing on changes related to time/age
Dr. Hernandez addresses the issue of research misconduct in her info session to introductory psychology students, who are candidates for a number of research studies at her university. A researcher at a nearby university has recently been accused of misconduct, so this topic has garnered significant press. Dr. Hernandez wants to share some insights with her students with regard to the publication process. Which of the following are accurate statements about the publication process that Dr. Hernandez might share with her students? Check all that apply
-The process of peer review involves carefully scrutinizing every aspect of research from justification to data analysis. -Reference citations must be included if someone else's work has merely influenced your own. -Researchers may commit fraud because of the pressures to "publish or perish."
Miles is studying visual memory function. He has recruited research participants from introductory psychology students. He shows a randomly selected one-third of the participants emotionally upsetting photos, shows another one-third very happy photos, and shows the last one-third neutral photos. He then tests visual memory and compares the scores of the groups. What design is Miles using?
Between-subjects
Some experiments use nominal or ordinal dependent variables. Because you cannot compute means for these variables, you cannot use an independent-measures t test or an ANOVA (F test) to compare means between groups. However, it is possible to compare proportions between groups using a
CHI-SQUARE
Rebecca is studying whether providing children with small financial rewards will increase the amount of time they spend studying math. Unfortunately, the children who are not receiving money learn about the children who are being paid and demand that they, too, be paid. This effect is referred to as:
Compensatory equalization
Suppose the goal of an experiment is to demonstrate a difference between the groups. Which of the following would be most helpful?
Decreasing within-group variability
You will be asked to complete a questionnaire about food. You will also be asked to keep a food diary for one week.
Description of Procedures
Lucas is evaluating a new, intensive treatment for generalized anxiety disorder. Halfway through the research, he finds that individuals in the standard treatment condition are typically continuing, but nearly half of the individuals in the experimental treatment condition have dropped out. Lucas is having problems with:
Differential attrition
Chi-Square
Eric is interested in children's choices of toys. He creates three sets of blocks—one set left a natural wood color, one set painted in bright primary colors, and one set painted in soft pastels. The outcome measure is whether or not his research participants, all boys, play with the blocks (the only toys in the room) or find some other way to spend the five minutes they are left in the "waiting room."
The results . from a two factor ANOVA show no main effect for factor A but a significant interaction. What can you conclude based on this pattern of results ?
Factor may have an effect but if so it depends on the level of factor B
What is the appropriate statistical analysis for evaluating the after treatment mean differance for a post test only none equivalent control group design
Independent measure T test
A professor tells his/her students that their grades will be lowered if they do not participate in his/her research.
Informed consent is violated.
What are some of the advantages of a between-subjects design?
It allows each individual score to be independent of all other scores.& It can be used to address a wide variety of questions.
Which of the following acurately describes a two factor analysis of variance?
It conducts three separate hypotheses test and produces three F ratios
How does sample size exert its effect in experiments?
It helps overcome high variance.
Different Relationship Types
Linear, Monotonic, Curvilinear
A strength of the cross-sectional design is that:
Long-term subject cooperation is not required
Incorporated deception in instructing participants to use electric shocks to punish other individuals when they made errors during a learning task
Milgrim
A factorial study measures allergy symptoms before and after taking medication for a group taking the real medication and a control group taking a placebo, what kind of design is being used ?
Mixed Design
The students in one gym class receive a self esteem program as part of their sports training to evaluate the program, a researcher measures self esteem for the students before and after the program and compares their scores with those from another class that did not receive the program but was measured at the same two times ,What kind of design is being used ?
Mixed Design
The goal of this study is to examine the relationship between beliefs about food and dietary patterns.
Overview
What impact did the Milgram study have on participants
Participants left the study feeling ashamed and embarrassed.
The National Research Act mandates that:
Protection of human participants is upheld
Which of the following statements are consistent with the APA guidelines with regard to nonhuman subjects? Check all that apply
Researchers using animals in research are subject to oversight by the Institutional Animal Care and Use Committee. - Researchers must proceed rapidly, with an effort to minimize pain, when an animal's life must be terminated.
The Advantages of Within-Subject Designs
Smaller Sample Requirements By Design By Statistics Control Over Differences Between Groups Between-Group Variance Control Over Differences Between Individual Within-Group Variance
created equally
The process used to obtain participants should be as similar as possible for all of the groups.
Because between-subjects experiments use a different group of participants for each treatment condition, one concern is that the participants in one treatment are noticeably different—for example, older, faster, or smarter—from the participants in another treatment. In the Katona experiment, how can the researcher be reasonably confident that the students in the understanding group were not considerably smarter than the students in the memorization group and that the difference in performance isn't simply caused by intelligence?
The two groups were roughly equivalent when assigned to the two treatments.
Dangers of Within-Subject Experiments
Third-variable interaction effects Internal Validity Issues Environmental factors (time of day, administrator) Time-related factors (internal changes over time) History/current events Maturation Instrumentation changes Testing/learning effects Order effects (changes brought on by the specific order) Carryover effects Testing/learning effects
What methods can be used to minimize variance within a treatment group?
Use a large sample size., Use random assignment and matching,Standardize the treatment setting and procedure ,Limit individual differences.
Which term refers to a statistical value that measures the size of the differences from one score to another?
Variance
Miles is studying visual memory function in a clinical setting. He recruits individuals in the early stages of dementia, administers a test of visual memory, and then tests them again after they have been on a medication that may slow the progress of dementia for a month. This is a
Within-subjects design
Pretest-Posttest Design
a design where a group is compared before and after the manipulation Note: these tests are considered quasi-experimental designs when some control was attempted and a manipulation occurred
Correlations (r)
a measure of the direction, strength, and nature of the relationship between two variables
which of the following is an example of . non experimental study
a study comparing self esteem scores for children with a learning disability vs scores for children without a learning disability
Within-Subjects Experimental Design
all of the benefits of this design are null if there are carry-over (third-variable) effects across conditions Teaching methods example
Graham is conducting a study of cognitive-behavioral methods for coping with social anxiety using a within-subjects design. He carefully finds a comfortable room that he can use for each experimental session, ensures that he has thoroughly trained the assistants who will be rating the behavior of his subjects, and prepares all of the necessary materials. All goes well at the first session, but halfway through the second session, the area erupts in sirens as a building a few blocks away is engulfed in fire. Graham should be concerned about
an environmental confounding
Graham is conducting a study of cognitive-behavioral methods for coping with social anxiety using a within-subjects design. He finds that the behavioral ratings provided by his observers are diverging. Which type of confounding may be occurring?
an instrumentation
The strength of the correlation and the significance of a correlation
are different
Negative relationship
as one variable increases, another variable decreases (r = -.01 to -1.00)
Positive relationship
as one variable increases, another variable increases (r = .01 to 1.00)
Zero
as one variable increases, no predictable change occurs in the other variable (r = 0.00)
Correlations can exist for multiple variables,
but the strength of the correlation is just as important as the direction (closer to 0 = weaker relationship)
Graham has completed a within-subjects study of cognitive-behavioral methods for coping with social anxiety. He is now talking with the subjects about their experiences. He learns that several of them combined the methods that they were being taught. That is, rather than just using the method that was taught at a particular session, they used that method and techniques they had learned in previous sessions. Graham should be concerned about
carry-over effects
in correlational research, there is no
categories for your independent variables. Each variable is quantitative. Categorical strength exception 0's and 1's for groups in IV or DV Implications Limitations
When the outcome measures are categorical, the ________ is the most appropriate test
chi square
what is the appropriate statistical analysis for comparing non numerical data for a differential design comparing samples representing two populations
chi square test for independence
Cohort effects
differences between groups caused by their distinct experiences
Which research design is used by a researcher comparing self esteem scores for children from divorced families vs scores from children from families with no divorce
differential research design
Another term for the between-subjects design is
independent measures design
The simplest version of a between-subjects experimental design involves comparing only two groups of participants: The researcher manipulates one independent variable with only two levels. When the measurements consist of numerical scores, typically, a mean is computed for each group of participants, and
independent-measures t test is used to determine whether there is a significant difference between the means.
For a between-subjects experiment, which of the following is a possible threat to internal validity?
individual differences that exist between treatments
In the nonexperimental pretest-posttest design, each
individual in a single group of participants is measured once before treatment and once after treatment.
In a between-subjects experiment, if the participants in one group have characteristics that are different from the participants in another group, then which of the following is threatened?
internal validity
Research ethics involves coming to a consensus about the appropriate and acceptable conduct of research. It
involves all types of research with both human and nonhuman participants and is not a matter of morality.
Correlations are usually obtained when
looking at two or more variables within ONE subject. However, this is neither necessary, nor always the case.
A_________________design can combine the advantages of within- and between-subjects designs.
matched-subjects
Vincent knows that performance on his test of cognitive flexibility is related to age, so he makes sure that for every person of a specific age in his treatment group, there is a person of the same age in his comparison group.
matching
Longitudinal developmental research design -
measuring variables of individuals over time Attrition concerns Time and cost concerns
In between subjects designs, participants are
only in one of the levels (conditions) of their independent variable
Graham has completed a within-subjects study of cognitive-behavioral methods for coping with social anxiety. Knowing that memory can be impaired by anxiety, one of the measures Graham included in his within-subjects study of cognitive-behavioral methods for treating social anxiety was a memory test. Since performance on memory tests often improves simply as a result of having more experience with them, Graham should be concerned about
practice effects
What design is being used by a researcher comparing depression scores before and after treatment in one group of clients ?
pre post design
Within the context of nonexperimental research, the variable that is used to differentiate the groups of participants or the groups of scores being compared is called the
quasi-independent variable.
George relies on the flip of a coin to assign participants to the treatment or comparison group.
random assignment
When the data from a within-subjects design experiment are on an interval or ratio scale, a_________________________can be used to assess treatment effects.
repeated-measures ANOVA
Several students in the comparison group respond quite differently to learning they are not in the treatment group and just give up, doing poorly on the tests at the end of the intervention
resentful demorilazation
In the world of research, the term_____________ Correct means that it is very unlikely that the difference would occur if there were not a consistent difference between the treatment conditions.
significant
Between-subject designs are
sometimes necessary and of benefit in comparison to within-subject designs
In quasi and non-experimental comparison designs, we're
still using the same types of variables (a comparison of (a) scale variable(s) across levels of nominal/ordinal groups)
Quasi-experimental research
studies that generate comparisons across groups where we don't have the ability to either a) assign participants into manipulation groups, and/or b) control for all potential extraneous variables
Between-subjects designs remove
the effects of contamination across conditions and are sometimes the only real option that we have
The primary disadvantage of a between-subjects design stems from
the fact that each score is obtained from a unique individual who has personal characteristics that are different from all of the other participants. Another is that they require a relatively large number of participants.
Whenever the individuals in one group have characteristics that are different from those in another group
the internal validity of the study is threatened.
Within-Subjects Experimental Design is
the most robust study, because we can account for most individual differences
Coefficient of determination (r2) -
the percent change in one variable that can be attributed to the change in another variable
A research study evaluates changes in behavior related to age by examining one group of participants who are all roughly the same age at different times. What is the name for this research design
A longitudinal developmental design
When research questions require more than two groups to evaluate the functional relationship between an independent and a dependent variable or need to include several different control groups in a single study, a single-factor multiple-group design may be used. In this case, the
ANOVA s used to test for the presence of a significant difference.
Rudy is diligent in ensuring randomization of the participants in his study on the effects of expectations on alcohol-related impairments. However, he subsequently finds that the participants in one of his groups have substantially greater experience with alcohol than do those in the other group. This difference is evidence of:
Assignment bias
What are big concerns with this non equvalent research
Assignment/selection bias - the process of creating groups that are inherently different to begin with Differential effect - situations where group differences can be explained by different histories or experiences
You may learn more about your food intake.
Benefits
A researcher wants to examine whether the size of the font of test questions affects scores on a test. The researcher gives 200 undergraduate students the same test, except that half of the students receive a test printed in size 10 font and the other half of the students' exams are printed in size 14 font. What type of design is this?
Between-subjects
What are the characteristics of these types of studies? Quasi and Nonexperimental
Both obtain information about a second variable of interest (this was the dependent variable in experimental studies) Both attempt to find differences between groups (just like experimental designs) Both can be conducted as either a between-subjects design (differential research, post-test), or a within subjects design (pre-post, time series)
Causation Issues
Causation is something that can be inferred from this type of research, but it is not a definite (otherwise it would be an experimental design)
What theorem relates to the notion that larger sample sizes creates less variability between groups?
Central Limit Theorem
What type of statistical analysis is most appropriate to use with a single-factor, multiple-group design in which the outcome measures are categorical and yield proportions?
Chi-square
Groups of individuals who were born at roughly the same time and grew up under similar circumstances are called:
Cohorts
Research ethics involves:
Coming to a consensus regarding appropriate conduct in research
What is one solution to the dilemma of clinical equipoise?
Compare treatments when there is uncertainty about which treatment is best.
A research study involves viewing television programming that is violently graphic in nature. Participants are not told that the study will involve viewing such images.
Informed consent may be violated.
According to the APA Ethical Principles of Psychologists and Code of Conduct (APA 2002, 2010), what characterizes informed consent?
Informed consent should be obtained using reasonably understood language.
Institutions that conduct research with animals have an animal-use review board called an:
Institutional Animal Care and Use Committee
Jason is performing a within-subjects experiment in which there are three treatment conditions. How many groups of subjects will he need?
Just one group of subjects is required.
One of the general ethical principles is "no harm"; that is, the researcher is obligated to protect participants from physical or psychological harm. In Hauner et al.'s study, what is the potential harm?
Long-term fear reaction to common smells
Graham has completed a within-subjects study of cognitive-behavioral methods for coping with social anxiety. He is looking over his data and notices that the individuals with the highest anxiety scores show a decrease in their scores, while there is little change in the scores of other subjects. This suggests the possibility of confounding by:
Regression
Rebecca is studying whether providing children with small financial rewards will increase the amount of time they spend studying math. Unfortunately, the children who are not receiving money learn about the children who are being paid, and as a result, quit studying. This effect is referred to as:
Resentful demoralization
Dominick is conducting a study on attitudes toward weight-loss methods. Because he believes that these attitudes may be related to weight, he decides to include only individuals whose body mass indices are 25.0 or higher. What method is Dominick using?
Restricted range
A clinical psychologist body measures body satisfaction for a group of clients diagnosed with anorexia nervosa each day for one week before and for one week after the psychologist begins a series of group therapy sessions. What kind of design is being used ?
Time series
What is one major reason why researchers use nonhumans as subjects?
To conduct research that is impossible to conduct using human participants
An important advantage of a within-subjects design is that:
Treatment effects and individual differences are not linked
Which research assistant is engaging in active deception?
Trey, who tells study participants the experiment focuses on eye functioning, when in fact it is on sexual attraction
What is the primary disadvantage of the between-subjects design?
Vulnerability to individual differences
A time-series design has
a series of observations for each participant before a treatment or event and a series of observations after the treatment or event.
Manipulation
changing one variable (independent variable) to determine its affect on another (dependent variable)
Cross-sectional design
comparing variables of individuals across ages at the same time
Cross-sectional longitudinal design
comparing variables of individuals across ages over time Less time and attrition concerns, but cost is still a big issue
How can order effects be measured and evaluated
counterbalance and use a factorial design with the order of treatments as a second factor
Which of the following is common in within subject experimental design but is impossible in a pre post design
counterbalance order of treatments
The purpose of___________________ Correct is to distribute order effects evenly across the different treatment conditions.
counterbalancing
A research study evaluates changes in behavior related to age by examining different groups of individuals with each group representing a different age. What is the name for this research design
cross sectional developmental design
Preexisting groups defined by age are examined in a
cross-sectional developmental design.
_____ studies are carried out
how
Which of the following is the primary threat to internal validity for non equivalent group design ?
individual differences between treatment groups
For which of the following studies does the researcher not control which individuals are assigned to which group
non equivalent group design
counterbalancing does not remove or control for
order effects and time-related factors, it just helps us adjust for them
Matched subject designs
pairing individuals that are considered equivalent and placing them into separate conditions
Which of the following is a possible use for a factorial design
replicate and expand previous research, examine order effects for a within subjects study, reduce variance in a between subjects study
One-group/individual pretest
posttest design - similar to a within-subjects experimental design, but there is no control for internal validity
What can a researcher determine by using a series of observations before treatment ?
scores are influenced by some factor unrelated to the treatment
counterbalancing only helps for
some of the order effects and time-related factors that we encounter
which of the following is the primary advantage of a pretest post test non equivalent control group design in a comparison with other non equivalent group design
the pre test scores can help reduce the threat of individual defferances between groups
The more variability we have
the tougher it is to determine that the groups are part of different populations
this also doesn't save you any participant # requirements, and
there is skepticism about ethically applying this method
Single-subject (case) designs
time series designs with only one participant/subject
In experimentation,
we were looking for causation to explain differences
For 3 or more level IV comparisons
we're calculating out a F statistic
For 2 level IV comparisons,
we're calculating out a t-statistic
In correlational designs,
we're looking for the strength of a relationship between variables Association purposes Prediction purposes Predictor variable (≈indep. var.) Criterion variable (≈dep. var.) Regression - the use of a change in one variable to predict a change in the other (Y' = aX + b)
you have a better chance of finding something in your research if
you end up running a within subject design
this also requires a lot of time and effort, and
your equivalence is only as good as your means of obtaining it
Between-subject experimental design
comparing two or more sets of scores across two or more groups of individuals to see how dependent variable values change across the groups
Within-Subjects Experimental Design
comparing two or more sets of scores within one group of individuals to see how dependent variable scores have changed across independent variable groups
Nonexperimental comparison research
comparisons across groups where manipulation is not possible, or when we have no ability to control for any extraneous variables
Several students in the comparison group figure out that they are not getting the new intervention and complain to an administrator. In order to avoid problems, the administrator takes it on himself to see to it that the students in the comparison group get his version of Faye's new treatment.
compensatory equalization.
Significance
the chance that the relationship between variables that was discovered is due to chance (actually measured with t statistics)