PSYCH 100B PRACTICE EXAM ANSWER KEY + KEY TERMS
Validity
1. EXTERNAL VALIDITY: how well can we generalize results aka how realistic/applicable is this to real life settings 2. INTERNAL VALIDITY: relationship/causation is true for our predicted relationship or is it messed up/cannot actually be inferred
The researcher did not control for the varying rates of crime in the neighborhoods to which the officers were assigned. However, crime rate could influence both workload and mood. Thus, crime rate represents
a third variable
floor effect
an experimental design problem in which independent variable groups score almost the same on a dependent variable, such that all scores fall at the low end of their possible distribution
The proofreading task is
an extraneous variable
Dr. Tran's study employs a ______ design with ______ levels of the independent variable.
between subjects; three
If Dr. Kipling elects to have different participants read each of the three types of materials, he will be employing a _____ and will need ______ subjects in his study
between-subjects design; more
What type of design has Sara used in her study?
between-subjects experimental
In this study, mood induction is a ____variable and word type (positive vs. negative) is a ___ variable
between-subjects; within-subjects
Because of the design used, one can only make causal conclusions about
both main effects and the interaction
An extraneous variable or variables in Mr. Roger's study is (are):
the kind of candy, and it is controlled the color of the bags containing the different numbers of candies, and it is controlled
The dependent variable in his study will be _____ and be measured on a _____ scale.
the length of time to read the first 1000 words of the presented material; ratio
observational / correlational variables
predictor variable vs response variable
Reasons to conduct a non-experimental study
-To observe behavior as it naturally occurs - If you are in the early stages of studying a topic
The judges in this experiment
-are an extraneous variable that is held constant - should be kept blind to the conditions experienced by each subject -must be evaluated to ensure inter-rater reliability
Which of the following threatens the external validity of the study?
-social psychology students may not be a representative sample of adults in the general population - people who volunteer to participate may not make up a representative sample of the general population - students who are interested in extra credit may not be representative of the general population - random sampling was not employed
The appropriate statistical test to analyze the data would be
. a one way ANOVA followed by appropriate posttest comparisons
In this study, the person observing the children's behavior is most accurately described as
. a possible source of observer bias; confounding variable
In order to analyze the data properly, the researcher would need to conduct
a two way ANOVA with a posttest if the interaction was significant (remember, ANOVAS can tell you main effect, but only posttest can help with understanding interaction significance)
The appropriate statistical test to analyze the data from this study would be
a one-way ANOVA followed by appropriate posttest comparisons*
The appropriate statistical test to use for the initial analysis of their data is
a one-way ANOVA.
The confounding variable would be eliminated if
a randomly selected half of the boy scouts and girl scouts tried cotton sleeping bags while the other half of the boy and girl scouts tried nylon sleeping bags
A causal relationship could be concluded from
a significant effect of speaker credibility only (only true independent variable)
Which of the following is true about this study
. in order to validate the construct validity of the music manipulation, it would be important to check whether the mood induction actually caused the desired changes in people's moods
This study has ___ independent variables and ___ dependent variables
1 ; 2
In this study there is/are _______ independent variable(s), each with ______ levels.
1 ; 4
Which of the following is true about a scientific hypothesis
- It must be testable -It is always considered tentative, regardless of how much evidence supports it -In the face of inconsistent evidence the hypothesis is questioned
Experimenter bias can be reduced by
- making the experimenters "blind" to which subjects are receiving which treatments. -by standardizing the experiment as much as possible (e.g., using tape-recorded instructions)
Bias
1. Experimenter 2.Participant -->Self-selection is a specific type of subject bias 3. Materials EXPERIMENTS SHOULD BE DOUBLE BLIND
How do we know there is no interaction?
1.Graph 2. Additive formula 3. Difference of differences: 1. Find difference of simple effect 1 2 - 10 = -8 2. Find difference of simple effect 2 10 - 18 = -8 3. Find the difference of those differences -8 - -8 = 0 4. Compare resulting number (0) to "magic" significance value so... A. C B. D a - c = x b - d = y x-y = booyah is booyah significant? -->Assume differences of 10 or greater are significant
In an ANOVA, which means would be compared to test for a possible main effect of praise?
10 and 11 (weak and strong praise)
This study is a
2X2 between subjects factorial design
How many experimental conditions are employed in this design?
4
If Dr. Bliss wants 10 subjects per condition, how many total subjects does she need for this study?
40
Which means should be used to ascertain the overall effect of therapy on depression?
44 and 19
The finding obtained in the professor's study suggests that
Amount of time spent sleeping may have been confounded with the students' interest in the topic for each lecture.q
nonequivalent group design
An experimental design whereby the researcher doesn't use random assignment, so the control group is not necessarily equivalent to the experimental group.
The height of the Duplo tower is
An extraneous variable held constant
how to graph?
BAR GRAPH: when the variable plotted on the x-axis is categorical; generally used to present and compare the mean scores for two or more groups or condition LINE GRAPH: when it is quantitative; used to present correlations between quantitative variables when the independent variable has, or is organized into, a relatively small number of distinct levels.
developmental studies
Because age is a variable used, developmental studies are inherently quasi-experimental studies
Which of the following is NOT TRUE about Andy's experiment?
Carryover effects could be a problem in this experiment
Materials Bias
Ceiling effect Floor effect Demand characteristic Specific Item effect
What can Dr. Tran conclude from his study?
Dr. Tran cannot conclude anything because of self selection
The appropriate statistical test for this study is
One-way between-subjects ANOVA followed by appropriate post tests
The type of design is
Quasi-experiment factorial with two quasi independent variables
If Dr. Ang had not randomly assigned subjects to the conditions, but rather had allowed them to decide which condition they wanted to be in, the study would have suffered from
Selection effects
SAMPLING BEHAVIOR
TIME SAMPLING:Narrows down behavior to be observed by limiting the amount of time we are observing EVENT SAMPLING:Narrows down behavior to be observed by limiting the specific behaviors we are observing; ignores all other irrelevant behaviors INDIVIDUAL SAMPLING: Narrows down behavior to be observed by limiting the number of subjects we are observing at one time; Observe one person (or small group of people) at once, before moving onto another
The independent variable in this study is
The price of the chocolate as described to the participants
Which of the following is/are true of the results of this study?
There appears to be a main effect of energy bar type, but no main effect of performance type
Which of the following is true with respect to this study?
`There is a confounding variable present in the study. The study employed a within-subjects design.
If the main effect of clothing is significant one could conclude that
a child dressed in girls' clothing is rated as less aggressive than a child dressed in boys' clothing
The design of the study is
a correlational design
The dependent variable in this study is
a self-report rating of happiness measured on an interval scale
To fix his study and change it into a true experiment, Havno should
add a condition in which no milk is consumed and randomly assign half of his 500 subjects to it
The independent variable(s) is (are)
age (13 or 18) b. appearance (shabby, dressy)
In this study, the independent variable was ____; the dependent variable was measured by ____; and an extraneous variable held constant was ____.
alcohol consumption; braking speed; time since alcohol consumption
Which of the following are extraneous variables in the study
all are extraneous variables
To test Professor Bjork's belief or hypothesis, Bill and Ted have conducted
an experiment in which sitting position was the independent variable and exam score was the dependent variable
interrupted time series
an experimental design in which the dependent variable is measured periodically across many time points, and the treatment occurs in the midst of such measures, OFTEN ONLY ONCE
ceiling effect
an experimental design problem in which independent variable groups score almost the same on a dependent variable, such that all scores fall at the high end of their possible distribution
The appropriate way to analyze the data from this study would be to use
an independent-samples t test
dependent samples t test
an inferential statistical analysis used when comparing two samples of data in either a matched groups design or a repeated-measures design
Given the description of his study, Mr. Roger's hypothesis about generosity would best be described as
children who have more will be more generous
In this study, the independent variable was the ______; the dependent variable was the ______; and an extraneous variable held constant was the ______.
color of the serving cup; ice cream ratings; amount of ice cream consumed
The product being advertised is
confounded with the gender of the person heard in the ad
Which of the following are possible confounding variables in the study?
confounding variable: A confounding variable is an "extra" variable that you didn't account for. They can ruin an experiment and give you useless results. They can suggest there is correlation when in fact there isn't. They can even introduce bias.
The type of research design used in this study was
correlational
Suppose Dr. Kipling decides to conduct his study as a between-subjects design, and he randomly assigns a sufficiently large number of participants to each condition. By using random assignment, Dr. Kipling will have
created equivalent groups b. controlled for differences in individual reading speeds among participants
criterion variable
dependent variable
John has organized his CD's using a
interval scale
Archival Research
method of research using past records or data sets to answer various research questions, or to search for interesting patterns or relationships (NO LIVE PARTICIPANTS)
Which of the following would be an appropriate interpretation of the interaction in this study, provided the study had high internal validity
more discipline problems in public preschool than in private preschool are seen only when the teacher is out of the room
By giving some students a set of problems containing only possible-to-solve problems and other students a set of mostly impossible-to-solve problems, Dr. Liu has
operationally defined his independent variable
Ringo has organized his CD's using a
ordinal scale
These three possible ways of collecting her data—that is, (a), (b), and (c) above, respectively—would produce data or measures that would fall on which types of scales, respectively.
ordinal; interval; ratio
The dependent measure used by Dr. HipHop
produced scores that lie on an interval scale
The independent variable in this study is
students' attendance at football games
The variable of mood is
the dependent variable
The researcher can conclude that
there is a negative association between workload and mood
Havno's study is not a true experiment because
there was only one level of the independent variable
specific item effect
this is a type of material bias - when a specific item affects the dependent variable - for example, if we were to see how well we remember the clothes that an animal is wearing and we choose an elephant to be one of the animals, if the subjects all absolutely love elephants, then the elephant would be the specific item that affects the dependent variable causing ceiling effects
Threats to Quasi-Experimental
u History effects - real-world, environmental change u Testing effects - testing multiple times influences test responses u Selection effects - systematic differences between participants in multiple groups u Maturation - participant growth, development or change u Mortality - participant drop out from the study u Statistical regression aka regression to the mean- extreme scores revert to the mean--> An extreme finding is likely to be closer to its own typical, or mean, level the next time it is measured
LEVELS OF MEASUREMENT
1. Nominal : named variables 2. Ordinal: named + ordered variables __socio economic status ("low income","middle income","high income"), education level ("high school","BS","MS","PhD"), income level ("less than 50K", "50K-100K", "over 100K"), satisfaction rating ("extremely dislike", "dislike", "neutral", "like", "extremely like"). (difference between each level varies; we decide that) 3. Interval: named + ordered variables + proportionate interval between variables (not true zero) aka difference matters --> temperature (Farenheit), temperature (Celcius), pH, SAT score (200-800), credit score (300-850). 4. Ratio: named + ordered variables + proportionate interval between levels + can accommodate absolute zero
TYPES OF MEASURES
1. Self-report: Relies on a person's assessment of their thoughts, feelings, beliefs, habits, etc. 2. Behavioral: Any behavior a person naturally does, or is asked to do u Observe participants and measure 3. Physiological: A biological measure
Reliability
1. Test-Retest Reliability: Ensure any instruments/measures you use are dependable 2. Interrater Reliability: Ensure ratings are consistent, no matter which particular person is making them
types of developmental studies
1. cross-sectional : between subjects, different participant groups are used at each age (at the same time) --> faster, BUT has COHORT EFFECTS (conceptualized as an interaction or effect modification due to a period effect that is differentially experienced through age-specific exposure or susceptibility to that event or cause 2. longitudinal (within subjects, same participant groups are used at each age, great for statistical strength b/c participants used as their own control, BUT has MORTALITY EFFECT (participants drop out) or HISTORY EFFECT (outside events may influence results) 3. sequential : Combines aspects of Cross-Sectional and Longitudinal Designs u Different participant groups are recruited and followed across time (also adopts both pros/cons)
Quasi-experimental design
1.Interrupted Time Series (can be different participants) ---> can suffer from [History effects - environmental or real-world changes] 2. Pretest-Posttest (same participants) ---> only one measurement before and after an event (time series has more records) --->can suffer from history effect and testing effect (being tested multiple times influences responses) --->can suffer from maturation: participants grow and develop --->can suffer from Mortality (Attrition) - participants drop out of study 3. Developmental Studies u ---->a.Cross-sectional ---->b.Longitudinal ----> c.Sequential 4.Quasi-factorial experimental 5.Ex Post Facto ("after the fact")--> contingency table ( --->a.Prospective(looks forward toward the future))--> u Find people who floss and do not floss, and FOLLOW forward through time u Can determine whether there is a relationship, but not that flossing CAUSES gum disease --->b. Retrospective(looks backward toward the past)--> Find people with and without gum disease, and determine whether they flossed at different rates u Still can determine whether there is a relationship, but not that flossing CAUSES gum disease
OBSERVATIONAL TECHNIQUES
1.Naturalistic --->a.Unobtrusive: Participants do not see the researcher --->b.Obtrusive: Participants know they are being watched (might have con: participant reactivity) 2.Participant: The researcher becomes part of the scene they are observing ---->concerns: Ethical? u Might your presence influence results?
If the interaction is significant and we want to know whether type of praise makes a difference when the task is easy, which means would we compare
12 and 18
The design of the study is a(n)
2 X 2 mixed subjects factorial design (between subjects for the first iv but within subjects for the second iv)
Which means should be used to ascertain the simple effect of therapy on depression when no anti depressant is used?
60 and 30
Which means should be used to check for an interaction between therapy and antidepressants on depression?
60, 30, 28, and 8
Balanced Latin Square Counterbalancing
A B D C B C A D C D B A D A C B controls for 1.Specific Item Effects 2. Order Effects 3. Sequence Effects -->16 Surveys, for 16 Participants
Suppose the researcher finds that the babies who were bathed before bedtime slept better in a dark room than in a room with a night light. This describes:
A simple effect
simple design experiment
A simple experiment is one researchers often use to determine if changes in one variable might lead to changes in another variable—in other words, to establish cause-and-effect
Which of the following accurately describe(s) a study with high internal validity?
A study in which all variability in the subjects' heart rates (used as the measure of the dependent variable) is shown to be due to the type of film they are required to watch (where different types of film define the different levels of the independent variable).
carryover effect
A type of order effect, in which some form of contamination carries over from one condition to the next.
QUANTIFYING BEHAVIOR
FREQUENCY method: Count the number of times the behavior occurs (TIME SPENT) DURATION method:Determine the amount of time spent engaging in the behavior INTERVALS method: Break the time into equal intervals ;Note whether the behavior is exhibited or not during each interval
After conducting this study, Dr. Liu finds that each subject completes nearly all of the arithmetic problems successfully and that the mean performance of the experimental subjects (M = 99%) and that of the control subjects (M = 98%) were not significant different. Which of the following could be the reason why Dr. Liu did not obtain a significant difference between the two groups.
He has a problem of ceiling effects
Examples of a positive correlation between two variables are
I. the more optimistic a person is, the better able they are to respond to stress II. the greater the number of traffic tickets a person has, the more likely they are to be involved in a traffic accident III. as unemployment levels drop, the suicide rate also drops
Examples of a negative correlation between two variables are
IV. the higher a student's GPA, the less money they are required to pay for car insurance V. babies born to women who smoke fewer cigarettes tend to be larger in birth weight
extraneous variable
In an experiment, a variable other than the IV that might cause unwanted changes in the DV. [INTERFERES WITH DV]
Which of the following is/are true about Mr. Unser's study.
In graphing his results, Mr. Unser should use a bar graph rather than a line graph.
self-selection bias
In statistics, self-selection bias arises in any situation in which individuals select themselves into a group, causing a biased sample with nonprobability sampling
ways to control extraneous variables
Keep it constant u Vary it randomly(Level or value is randomly distributed across participants) u Counterbalance it across conditions(Every condition has an equal chance of being affected by the EV)
event sampling
Narrows down behavior to be observed by limiting the specific behaviors we are observing; Ignores all other behavior and simply watches for a particular type of behavior
Dr. Hook is interested in whether people read different types of material at different rates. Subjects are asked to read one humorous story, one mystery story, and one sad story, each of which was written by a different author. The stories are presented in all six possible orders, with equal numbers of subjects receiving each order. Dr. Hook records the length of time it takes subjects to read the first 100 lines of each story.
Short Practice Exam 1 SPRING 2020.
Methods of Sample Selection
Simple Random Sampling: Every participant in the population has an equal chance of being chose; very challenging with large population u Stratified Random Sampling : Participants are randomly selected from specific demographic categories (or strata) u Proportionate to their frequencies in the population u Convenience Sampling: Participants are volunteers willing to come to the study; limits external validity
After the appropriate statistical analysis is performed, suppose that a significant effect of study method is obtained. What would the company be able to conclude?
Subjects using the critical-analysis method were able to answer significantly more items correctly than subjects using the traditional method. b. Making subjects engage in either the traditional or the critical-analysis method of study is better than leaving them to study however they want. c. Method of study had a significant effect on test performance
Suppose the ANOVA reveals a significant interaction but not a significant main effect of praise. Dr. Drew would be justified in concluding that
The effect of praise on performance depended on the level of task difficulty
Which of the following are extraneous variables in the study
The type of exercise subjects did
Which of the following is/are true of this design?
There are two independent variables in this study: 1 quasi IV and 1 true IV. Doris has employed a between-subjects factorial design.
Characteristics of Correlational Studies
Two variables are measured (not manipulated) u Both variables must be quantitative u Can determine a predictive relation u Can make predictions based on results, but not conclusions about causation predictor variable vs criterion variable We CAN make predictions based on this knowledge u We CANNOT determine causation
Dr. Smirnoff investigated the relationship between alcohol intake and reaction time in a driving simulation. One group of participants was given one ounce of alcohol to drink; another group was given three ounces of alcohol to drink; and a third group was given five ounces of alcohol to drink. Then, after the same amount of time had elapsed since consuming the alcohol, participants in each group were placed in a simulated driving situation. At a random point for each participant in each group, a red light suddenly appeared, and the time it took each participant to step on the brake pedal after presentation of the red light was measured.
Use the following terms to answer the next three questions about this study. a. timing of the red light b. speed of stepping on the brake c. time since alcohol consumption d. amount of alcohol consumed e. degree of intoxication 18. The independent variable used in this study was (D). 19. The dependent variable used in this study was (B). 20. An extraneous variable held constant in this study was (C).
Because subjects were matched on their initial test scores
We can assume that the researcher was concerned about controlling individual differences in memory abilities; The internal validity of the study has been enhanced
factorial design
Why conduct a factorial design experiment? 1. To test the effect of multiple IVs on the same DV; to control a particularly important EV ; To examine interactions
Choosing the Right Statistical Test : T Test vs ANOVA
[T-TEST/ONE IV WITH TWO LEVELS] ---> if Between Subjects: Independent Samples ---> if Within Subjects: Dependent (Paired) Samples [ONE WAY ANOVA, ONE IV WITH THREE OR MORE LEVELS] --> With post hoc tests! ---> The ANOVA will only tell you there is a main effect, not specifically where the difference is. TWO IVs = Two-way ANOVA -----> These tests can tell you whether there are significant Main Effects and Interactions THREE IVS = Three-way ANOVA --> Post hoc tests are required following any test involving more than two groups fOUR IVs = Four-way ANOVA -----> Main effects examining three or more levels/ Interactions
In this study the actual age of the girl in the photograph is ______; whereas the age described in the resume is _____
a constant; a between subjects variable
Dr. Earl E. Bird believes that people are better off waking up early rather than late. In support of his belief, he has observed that people who wake up early tend to be more productive than people who sleep late. What Dr. Bird has observed is
a correlation
Because she is looking at the amount of money people spend, Marcia is using a _____ measure that is measured on a(an) _____ scale.
behavioral ; ratio
In Bill and Ted's study, the exam score variable represents a _____ type of measure, and it was measured on a _____ scale
behavioral; ratio
What type of design is Dr. Bliss using?
between subjects factorial design
Dr. Young, a developmental psychologist, studied dependency by measuring how many times children in school asked an adult for help. Another developmental psychologist, Dr. Kidd, argued that asking for help was not a good measure of dependency. In fact, Dr. Kidd argued that asking for help shows resourcefulness and initiative. Dr. Kidd is disputing the _______ of Dr. Young's measure of dependency.
construct validity
confounding variable
extraneous factor that interferes with the action of the independent variable on the dependent variable [INTERFERES WITH IV, WHICH INTERFERES WITH DV]
Because he is recording only discipline problems, Jason can be said to be
event sampling
The design used in this study is
experimental, where time of day is the independent variable
Face validity
extent to which respondents can tell what the items are measuring
external validity
extent to which we can generalize findings to real-world settings
Because Mr. Unser used road hazards one is likely to find when traveling, and measured actual tire damage to assess durability, his study is high in
external validity
The independent variable in this study
has two levels: Dance A and Dance B
A track coach is trying to decide whether to buy Nike or Reebok track shoes for his sprinters. He decided to perform an experiment to see which shoe will produce the faster running times. He can properly test this question using a within-subjects design by
having a random half of the sprinters first run with Nikes and then run with Reeboks, while the other half first run with Reeboks and then run with Nikes
What is true about the order in which the photos are shown to subjects?
if Camille randomizes the order in which the pictures are shown that means that a subject might see the same hair color twice in a row
If the main effect of environment is significant, one could conclude that
in general, behavior is rated as more aggressive when the child is outside
masking variable
in statistics, the obscuring of the effect of one variable by the effect of another variable.
What type of statistical analysis would Bill and Ted have performed on the data they collected?
independent samples t-test
The relationship of the observers (peer and supervisor) to the subject is
independent variable
In Dr. Liu's study, the measures of his dependent variable would lie on a(an) _____ scale.
interval scale
This study
is a within subjects design
The amount of time that students study
is an extraneous variable that was controlled
The amount of time that students practiced
is an extraneous variable that was held constant
Based on the study he conducted and the results obtained, Dr. Bill's conclusion
is not warranted because there could be a third variable problem operating; for example, the age of the natives
One of the variables in this study is sex of the subject. Which of the following is true of this variable
it is a quasi-independent variable ; it is a variable that cannot be manipulated
One of the variables in this study is the credibility of the speaker. Which of the following is true of this variable
it is a true independent variable
The problem with the professor's conclusion is that the study
lacks internal validity
What is/are confounding variable(s) in this study?
location subjects are told that the chocolate was made
Based on these data, which of the following is the most likely outcome of the study? Assume a significance cutoff of 3 (where differences greater than 3 are significant).
main effects of both variables and an interaction
To be confident about any conclusions drawn from this study, the advertising executive should:
make sure that the commercials are shown in different orders to different subjects
The best way to describe the hypothesis being tested in Dr. Liu's study would be that
making people feel frustrated will cause them to behave aggressively
inter-rater reliability
measure of agreement among observers on how they record and classify a particular event
The dependent variable is
measured on a ratio scale
The dependent variable is
measured on an ordinal scale
quasi-independent variable
n experimental design, any of the personal attributes, traits, or behaviors that are inseparable from an individual and cannot reasonably be manipulated. These include gender, age, and ethnicity.
. What can Sara conclude from her study?
no conclusion can be drawn because of the presence of a confounding variable in the study
Suppose Dr. Liu uses an independent-samples t test to analyze the data collected in his study and finds that the mean rating of the questions asked by the students who were given the Set A problems (M = 2.3) was significantly different from the mean rating of the questions asked by the students who were given the Set B problems (M = 6.2). Would Dr. Liu then be justified in concluding that the frustration he created in students by making them work on impossible-to-solve problems caused them to ask questions in an aggressive manner?`
no, because there is a confounding variable present in his study no, because he has not used the correct test to analyze his data
Based on the type of study conducted by Bill and Ted, is there merit to the critic's point?
no: differences in intelligence are controlled by random assignment
Paul has organized his CD's using a
nominal scale
Because listeners overestimated the intoxication level of mildly intoxicated subjects and underestimated the intoxication levels of those who were completely drunk, this demonstrates
none of the above
Because the study included recordings of sober volunteers
none of the above
Dr. Bhatt can conclude that
none of the above
The researcher can conclude
none of the above
A critic of Bill and Ted's study claims that individual differences in intelligence might make the interpretation of the results of their study difficult. In this study, intelligence definitely is:
none of the above (not confounding because it order sequence and variance of intelligence was addressed with random assignment)
In order to establish inter-rater reliability, it would be important for Mr. Unser to have done which of the following
none of the above are related to inter-rater reliability
A possible problem with Dr. Turbo's conclusion is that
practice was confounded with time of day. type of video game varied systematically with levels of the independent variable.
A pediatrician reads the study and feels that type of feeding may also play a role in how well a baby sleeps. She asks her patients whether they bottle-feed or breast-feed their babies, asks them to put their babies to sleep in a dark room for 30 days, and count how many times their infant wakes up during the night. Which of the following is true?
none of the above are true
The following is (are) NOT true with respect to this study:
none of the above are true about this study
Suppose Dr. Green finds that, compared to the no-pollution condition (M = 75), the performance of subjects in the noise pollution condition (M = 65) was significantly worse, whereas the performance of subjects in the air pollution condition (M = 71) was not. Dr. Green would then be justified in concluding that
none of the above due to the presence of a confounding variable
Suppose Dr. HipHopo analysed her data correctly and found no significant difference between the scores of students that danced alone (M=6.6) and the students that danced in pairs (M=6.8). Based on this result, Dr. HipHop can conclude
none of the above due to the presence of a confounding variable
Before running this study as described above, the company should
none of the above; that is, none of the above is a problem with the study as described
On the basis of this study, the director will be able to conclude that the supplement decreases people's levels of stress if
none of the above; that is, none of the above outcomes would justify coming to this conclusion
About which effects could Jason make a causal conclusion
none of the effects because the presence of a confounding variable threatens the internal validity of this study (confounding bc it cannot be controlled; there's two different participants!)
. Unless proper control procedures had been used in this study, a possible problem could arise from
nonequivalent groups b. adaptation or drug tolerance effects c. differential driving skills among the participants
Unless proper control procedures had been used in Mr. Robbins study, a possible problem could arise from
nonequivalent groups (no random assignment) different degrees of liking for ice cream among the participants
Dr. Green's conclusions are
not justified because causality cannot be inferred
Professor Lee's conclusion is
not warranted because her study lacks internal validity
. Brent conducts a study on people's preference for sugar over saccharin. He makes a cake with real sugar and brownies with saccharin, and brings them to his local supermarket. As people walk by, Brent offers them a dollar to taste the two desserts and choose the one they prefer. Brent finds that people prefer the brownies. From this outcome, he can conclude
nothing because the study suffers from the presence of a confounding variable
order effects (sequence effects)
occur when participants' responses are affected by the order of conditions to which they are exposed aka When order becomes confounded with levels of the IV 1. practice effects 2. fatigue effects 3. carryover effects
In this study there is/are
one independent variable with four levels
What analysis should she use to determine whether the difference between conditions is a significant difference?
paired-samples t test (because within subjects)
matched random assignment
participants are matched into homogenous blocks, and then participants within each block are assigned randomly to conditions
Dr. Tran's measure of his dependent variable is a ______ measure, and its values lie on a ______ scale
physiological; ratio
simple random assignment
placing participants in experimental conditions in such a way that every participant has an equal chance of being placed in any condition
In this study, the criterion variable is__________ and is measured on a ________ scale.
pushups; ratio
Dr. Green is examining the effects of a _____ type of independent variable, with ____ levels
qualitative; three
In his study, Dr. Kipling will be manipulating a _____ independent variable with _____ levels.
qualitative; three
In order for Mr. Roger's study to be a true experiment, the amount of candy in the bag (20 or 40 pieces) for a given child should be determined
randomly.
George has organized his CD's using a
ratio scale
The scale being used to measure the dependent variable is _____, and Dr. Tator should analyze the data using a _____.
ratio; dependent samples t test
The independent variable used a _____ scale; the dependent variable used a _____ scale.
ratio; ratio
Suppose Dr. Kipling finds a significant effect of his independent variable (that is, after conducting the appropriate ANOVA, he obtains a significant F-ratio for his independent variable). He will then be able to conclude that
reading rates differ among the three types of materials used, at least as measured in his study
The dependent variable in this study was _______ and it was measured on a _______ scale.
recall ability; ratio
Assume you want to design a study that requires half of your subjects to bungee jump and half to sit still. What is the way to handle the fact that some may refuse to bungee jump?
recruit subjects who are willing to bungee jump and then randomly assign them to either bungee jump or sit still
Two researchers are observing the frequency of selfish behaviors of a child in a day care center. Both observers watch the same child during the same hour. When they later compare their written notes, they find that their results are drastically different. This discovery is usually described as a problem with
reliability
The measure of the dependent variable is
self-report
If Dr. Lucero elects to do (b), she will be using a _____ type of dependent measure, and if she does (c), she will be using a _____ type of measure.
self-report; behavioral
A confounding variable in this design is
sex of the scout
In his study, Dr. Liu has used a _____ procedure and a _____ measure of his dependent variable, and he should use _____ to analyze the data collected.
simple random assignment; behavioral; an independent-samples t test
The independent variable in this study is
study group size
The dependent variable in the study is
subjects' reading rates for the different types of stories
Dr. Hershey ran an experiment in a lab at UCLA to find out how the price of a food can affect perceived quality. He recruited participants for a chocolate tasting study. Before the participants tasted the chocolate, he told half of them that it was made in Switzerland and each piece cost $15. The other half were told that it was made in California and each piece cost 25 cents. Even though everyone tasted the same vanilla flavored milk chocolate, the participants who were told each piece cost $15 overwhelmingly rated the chocolate highly while those told it cost 25 cents rated it as inferior. After subjects gave their rating they were invited to eat as much of the chocolate as they wanted before leaving the lab.
telling the participants where the chocolate was made introduced a confounding variable into the study
A confounding variable in this study is
the authors of the stories
Which of the following is true regarding this study
the class section in which subjects are enrolled is a confounding variable
Suppose Dr. Lucero finds that children play significantly longer with Toy A—a robot that can be taken apart to form various types of futuristic looking weapons—versus any of the other three toys (B, C, D), which are a type of puzzle, a video game that requires counting, and a word-matching card game. She thus recommends to the CEO that the company market Toy A. After hearing the details of Dr. Lucero's study, however, the CEO complains that how long children played with each toy might not indicate how likely their parents would be to buy that toy. The CEO is questioning
the construct validity of the dependent measure
After hearing about the study, the president of the bubble-gum company complains that people's memory for the details of television commercials may not indicate how likely those people will be to buy the gum that was advertised. The president is questioning
the construct validity of the dependent variable
One of Clara's colleagues suggests that ratings of intelligence and attractiveness may not really provide a good measure of prejudice. The colleague is thus questioning ____
the construct validity of the operational definition of the dependent variable
internal validity
the degree to which the effects observed in an experiment are due to the independent variable and not confounding variables
The number of blocks the children use to build the Lego tower is
the dependent variable
face validity
the extent to which a test item appears to fit the particular trait it is measuring
construct validity
the extent to which variables measure what they are supposed to measure; Does your operational definition accurately measure your construct?
Jason's method of quantifying student behavior is best characterized as
the intervals method
The operational definition of generosity in Mr. Roger's study is
the number of tootsie rolls the children gave away
In this study, how long a native has been eating meat is
the predictor variable; a variable whose values are measured by use of a self-report measure
The safety of red dye #2 was tested on parrots. Five groups of parrots received differing amounts of the dye in their diets. One group ate no red dye in their diet while the other four groups had 1%, 2%, 3%, and 4% of their diets respectively infused with the dye. After six months on the red dye diet, a sample of blood was drawn from each parrot and the white blood cells were counted. Suppose the results show no statistically significant difference between groups. Which of the following is true:
the range of the independent variable may be too narrow to show differences
Which of the following is true about this study?
this is a within subjects design b. the order in which subjects participate in the conditions is a controlled extraneous variable
Demand Characteristics
those aspects of an observational setting that cause people to behave as they think someone else wants or expects
Which of the following is (are) true about this study?
time of class is confounded with the independent variable type of food consumption is the independent variable
The independent variable has ____ levels and is ______ - subjects
two ; within
In this study there is/are
two true independent variables
What statistical analysis is appropriate for this study?
two-way between-subjects ANOVA
The number of independent variables in Mr. Roger's study is
two: 20 tootsie rolls and 40 tootsie rolls
Replication
u Direct replication - the specific study design is copied as precisely as possible u Conceptual replication - the same research question is investigated using different procedures
Additive Effect
u The two variables do not interact u Their effect is additive u (B + C) - A = D A C B. D
If Marcia decides to offer this unlimited credit to her customers and then compares sales for 12 months before and after the policy is introduced, she is
using an interrupted time-series design to test the effect of the policy
If Dr. Kipling elects to have each participant read all three types of materials, he will be employing a _____ and will need to control for _____ .
within-subjects design; presentation order of the three types of material
By definition, developmental studies that are conducted longitudinally are ____, whereas cross sectional designs are _____ .
within-subjects designs; between-subjects designs
A cognitive psychologist, Dr. Holyoak, conducted an experiment to see if background noise would affect problem solving ability. In his study, 40 randomly chosen subjects were required to solve the same ten thought problems in a noisy setting while all other conditions (such as temperature of the settings, time of day, etc.) were held constant. All subjects were able to solve all 10 problems so Dr. Holyoak concluded that noise does not affect problem solving ability. As described, Dr. Holyoak's conclusion from this study
would not be warranted because there is only one level of the IV
Observational research should be used when
you know that your presence will have an effect on subjects' behavior
