Question 1

Pete wanted to see whether caffeine intake increased a subject's arousal state. He randomly assigned 100 high school seniors to an experimental or control group. The experimental group drank a high caffeine soda, while the control group drank a caffeine-free soda. He then measured and compared arousal states for both groups. What type of design did Pete use?
A) interrupted time series
B) two-group posttest-only design
C) classical experimental
D) pretest-posttest

Accepted Answer

Pete used a two-group posttest-only design, where one group received the experimental treatment (high caffeine soda) and the other group served as the control (caffeine-free soda), with the outcome (arousal states) measured after the intervention.

Question 2

Which of the following is LEAST suited to providing clear evidence about a CAUSAL relationship between two variables?
A) posttest only control group design
B) Solomon four-group design
C) classical experimental design
D) one-shot case study

Accepted Answer

The one-shot case study is least suited for establishing causal relationships because it lacks a control group and pretest measurements, making it impossible to determine whether any observed changes are due to the treatment or other factors.

Question 3

What is the Hawthorne effect?
A) A reactivity effect named after a famous case in which subject responded to the fact that they were in an experiment more than to the treatment. In effect, the experiment became the independent variable.
B) It is a special instrument for measuring emotionally charged attitudes invented in the 1930s Hawthorne, England.
C) When subjects do not receive the real treatment and instead receive an imitation treatment but respond as though they have received the real treatment. In effect, the belief that they received a treatment effects their behavior.
D) It is a type of experimental design using three control groups developed by Sir Thomas Hawthorne in the 1960s when investigating the effects of noise on mental concentration.

Accepted Answer

The Hawthorne effect refers to the phenomenon where individuals alter their behavior due to the awareness of being observed, as famously observed in the Hawthorne Works studies where workers' productivity changed when they knew they were being studied, not necessarily due to the experimental conditions themselves.

Question 4

The Solomon four-group design combines which two other designs?
A) classical experimental and equivalent time series
B) classical experimental and two group posttest only
C) one group pretest-posttest and static group comparison
D) case study and two group posttest

Accepted Answer

The answer of The Solomon four-group design combines which two...

Question 5

An experimenter says "it was a 3 by 3." What does this mean?
A) It was a time series design with three Xs and three Os.
B) It was a Latin Square design with three groups.
C) It was a factorial design with two variables, each had three levels.
D) It was a factorial design with three independent variables.

Accepted Answer

This refers to a factorial design where there are two variables (factors), and each variable has three levels. A "3 by 3" factorial design means that there are two dimensions being studied, with each dimension having three variations or levels.

Question 6

The speed limit on interstate highways in the United States was reduced from 65 to 55 miles per hour in 1976. It was raised back to 65 in 1988; in 1996, individual state governments could decide the limit and many raised it to 75 miles per hour. Proponents and critics of the law have looked at the number of traffic deaths per 1000 miles driven on the highways between 1970 and 1998 to see whether the law affected traffic deaths. What type of design is this?
A) one shot case study
B) pretest-posttest one group design
C) interrupted time series design
D) equivalent time series design

Accepted Answer

This is an interrupted time series design because it examines the impact of a policy change (speed limit laws) over time, before and after the intervention, using continuous data points.

Question 7

Several people criticized Dr. Gordon's classroom experiment on the effects of density of living conditions on aggression due to issues of external validity. This means problems with
A) posttest effects.
B) generalizability.
C) ethics.
D) randomization to the experimental or control group.

Accepted Answer

External validity refers to the extent to which the results of a study can be generalized to other situations and to other people. When critics point out issues of external validity, they are concerned with the generalizability of the study's findings.

Question 8

Yolanda wanted to test the effectiveness of a new 4-hour anger management treatment session. She first took 24 clients who had been referred for anger management pre-test) in March and divided them randomly into two groups. One group was assigned to the new 4-hour session, the other group went to a traditional anger management session. Each was given an in-take assessment measuring anger management skills. After clients finished the two-week sessions, she measured the level of anger management skills among all clients in both groups. What experimental design did she use?
A) time series
B) classical experiment
C) one-shot case study
D) static group comparison

Accepted Answer

Yolanda used a classical experiment because she randomly assigned clients to two groups, one of which received the new treatment and the other of which received the traditional treatment. She then compared the level of anger management skills among clients in both groups after they finished the two-week sessions.

Question 9

Dr. Useem designed an experiment on group competition to be realistic. She divided subjects into 6 three- person teams. Only one could "win" a race to assemble a large complex toy. She wanted subjects to get "caught up" in the situation so it would have a large impact on them. A confederate posed as the vice president of a toy manufacturer who offered each member of the winning team $300, but members of the 5 losing teams got nothing. She's trying to create
A) experimental realism.
B) mundane realism.
C) internal validity.
D) generic realism.

Accepted Answer

Experimental realism is achieved when participants become fully engaged in the experiment, which is what Dr. Useem aimed for by creating a competitive and rewarding scenario.

Question 10

During the course of her experiment, Yolanda learned that 7 of the 12 clients in her new 4-hour session had quit and walked out of the session before it was completed. What threat to internal validity does her experiment have?
A) experimental mortality
B) history effect
C) selection bias
D) maturation

Accepted Answer

Experimental mortality refers to the loss of participants from a study before it is completed, which is exactly what happened in Yolanda's experiment when 7 out of the 12 clients quit before the session was completed. This can threaten the internal validity because it might mean the results are not representative of the entire group that was initially intended to be studied.

Question 11

Dr. Marshall conducted an experiment to test changes in sex roles due to spending an entire day reading about the achievements of great women artists and scientists. The experimental group read fifteen articles about great women. The control group read fifteen articles about cooking, automobiles, astronomy, and accounting. During the lunch break, subjects from the experimental and control groups met and talked about what they were reading. What internal validity problem may occur?
A) experimental mortality
B) maturation
C) diffusion of treatment
D) testing

Accepted Answer

Diffusion of treatment occurs when information or behaviors from the experimental group are shared with the control group, potentially contaminating the results. In this case, the experimental and control groups meeting and discussing their readings during lunch could lead to this issue.

Question 12

The classical experimental design contains all of the following, EXCEPT
A) pretest and posttest measures.
B) random assignment of subjects.
C) an experimental and control group.
D) at least two different independent variables.

Accepted Answer

Classical experimental design typically involves a pretest and posttest, random assignment of subjects, and an experimental and control group, but it does not require at least two different independent variables. It often focuses on the effect of a single independent variable on a dependent variable.

Question 13

The following design notation for an experimental design is called
 0 0 0 0 0 0 0 0 0 0 X 0 0 0 0 0 0 0 0
A) equivalent time series.
B) Solomon four-group.
C) interrupted time series.
D) classical experimental.

Accepted Answer

This design notation represents an interrupted time series design, where observations are made multiple times before and after a treatment (X) is introduced. This allows for the examination of the treatment's effect over time.

Question 14

Dr. Bootsma designed and produced a 30 second radio commercial for a local automobile dealer. Next, she had the three most widely listened to radio stations in town play the commercial 15 times a day, everyday, for two weeks. She waited until the end of the two-week period, then she called Jack to see what his sales had been lately. What experimental design did she use?
A) time series
B) one-shot case study
C) static group comparison
D) classical experiment

Accepted Answer

The one-shot case study design involves a single group being exposed to a treatment and then observed for an outcome, without a control group for comparison. In this scenario, the commercial was aired, and then sales were checked, fitting this design.

Question 15

If the time between the pretest and the posttest is very short, then
A) the maturation effect is less likely to occur.
B) the instrumentation effect is more likely to occur.
C) the history effect is more likely to occur.
D) the statistical regression effect is less likely to occur.

Accepted Answer

When the time between the pretest and the posttest is very short, individuals have less time to change in ways that are unrelated to the intervention, making the maturation effect (changes due to the natural development or aging process) less likely to occur.

Question 16

After conducting an experiment on group dynamics, Dr. Smith performed an ethical debriefing. What is Dr. Smith doing?
A) Telling the subjects what the experiment is really all about, because he had lied to them earlier.
B) Telling the subjects a story to deceive them, so they won't know the true hypothesis being tested.
C) Administering a follow-up survey to check for latent effects of the experiment.
D) Encouraging subjects to provide names and phone numbers of their friends and family, so Dr. Smith can recruit more subjects.

Accepted Answer

An ethical debriefing involves informing the subjects about the true nature and purpose of the experiment, especially if deception was used during the study. This process is crucial for maintaining ethical standards in research.

Question 17

Dr. Duffy conducted an experiment to raise I.Q. scores by having experimental subjects eat three bananas a day for a month, while control groups had no bananas. Below are his results scores = average I.Q. score for group of subject). $$\begin{array} { l l l } 
& \text { Pretest } & \text { Posttest } \
\hline \text { Experimental Group } & 102 & 110 \
\hline \text { Control Group } & 80 & 110
\end{array}$$ Which of the following can you say about the results?
A) The experiment proves that the Dr. Duffy's treatment works.
B) The experiment has a statistical regression issue.
C) The experiment has history effects.
D) The experiment has selection bias problems.

Accepted Answer

The control group started with a significantly lower average I.Q. score (80) compared to the experimental group (102), indicating that the groups were not equivalent at the beginning of the study. This discrepancy suggests that the experiment has selection bias problems, as the initial differences between the groups could account for the observed outcomes rather than the treatment itself.

Question 18

What are "demand characteristics" in experimental research?
A) When neither the subjects nor an assistant helping the experimenter know specifics about the treatment or how hypothesis is being tested.
B) When subjects in a control group "demand" to be treated the same as the subjects receiving the treatment.
C) When an experimenter deceives subjects about the experiment's true nature, then later tells them what it is really about.
D) When subjects pick up clues about the hypothesis of the experiment and change their behavior to do what they think will confirm the experimenter's hypothesis.

Accepted Answer

Demand characteristics refer to cues in an experiment that make participants aware of what the experimenter expects to find or how participants are supposed to behave. This awareness can lead participants to alter their behavior in a way that they believe aligns with these expectations, potentially skewing the results of the study.

Question 19

Internal validity is threatened when subjects in the control group modify their behavior to compensate for not receiving the experimental treatment. What is this called?
A) maturation effect
B) experimenter expectancy
C) compensatory behavior
D) diffusion of treatment

Accepted Answer

Compensatory behavior occurs when subjects in the control group change their behavior because they know they are not receiving the experimental treatment, often in an attempt to compensate for this lack. This can threaten the internal validity of an experiment by introducing differences between the control and experimental groups that are not due to the independent variable.

Question 20

Field experiments, compared to laboratory experiments, generally
A) have equal external and internal validity.
B) have higher external validity and lower internal validity.
C) have lower external validity and lower internal validity.
D) have lower external validity and higher internal validity.

Accepted Answer

Field experiments typically have higher external validity because they are conducted in natural settings, making their findings more generalizable to real-world situations. However, they often have lower internal validity due to less control over extraneous variables.

Quiz 9: Experimental Research

Which of the following is LEAST suited to providing clear evidence about a CAUSAL relationship between two variables?

What is the Hawthorne effect?

The Solomon four-group design combines which two other designs?

An experimenter says "it was a 3 by 3." What does this mean?

Several people criticized Dr. Gordon's classroom experiment on the effects of density of living conditions on aggression due to issues of external validity. This means problems with

During the course of her experiment, Yolanda learned that 7 of the 12 clients in her new 4-hour session had quit and walked out of the session before it was completed. What threat to internal validity does her experiment have?

The classical experimental design contains all of the following, EXCEPT

The following design notation for an experimental design is called 0 0 0 0 0 0 0 0 0 0 X 0 0 0 0 0 0 0 0

If the time between the pretest and the posttest is very short, then

After conducting an experiment on group dynamics, Dr. Smith performed an ethical debriefing. What is Dr. Smith doing?

What are "demand characteristics" in experimental research?

Internal validity is threatened when subjects in the control group modify their behavior to compensate for not receiving the experimental treatment. What is this called?

Field experiments, compared to laboratory experiments, generally