Chapter 2: Research Methods

The observation in a classroom that the higher the room temperature, the lower student performance would be an example of: (A) Negative correlation (B) Zero correlation (C) Positive correlation (D) Independent correlation (E) Dependent correlation

(A) A negative correlation is expressed as - 1. This means that as one variable goes up, the other variable will go down. In this case, as the room temperature went up, the student performance went down, indicating a negative correlation.

Which of the following coefficients of a correlation indicate the weakest relationship between two variables? (A) 0.51 (B) -0.28 (C) 0.08 (D) -1.00 (E) 1.00

(A) A negative correlation is expressed as - 1. This means that as one variable goes up, the other variable will go down. In this case, as the room temperature went up, the student performance went down, indicating a negative correlation.

A random sample can best be defined as: (A) A sample in which each potential participant has an equal chance of being selected (B) A sample that is carefully chosen so the characteristics of participant: correspond to the larger population (C) A selection of cases from a larger population (D) A selection of cases from the control group (E) A sample of a larger population from the experimental group

(A) A random sample is defined as a sample in which each potential participant has an equal chance of selection. Choice (B) defines representative sample. Choice (C) defines the term sample, not random sample. Choices (D) and (E) do not accurately define random sample.

Marc, a psychology major, collected survey data about the number of hours that college students study for finals and their grades on those finals. His data indicates that students who spend more time studying for finals tend to do better than other students. What can Marc now conclude? (A) Studying improves a student's grade on a final exam. (B) A relationship exists between studying and exam grades. (C) A significant relationship exists between studying and grades. (D) Students who do not study for final exams will not do well on those exams. (E) Students with higher IQs tend to study more than those with lower IQs.

(B) Marc has established a relationship. Marc did not conduct an experiment; therefore, he cannot draw any conclusions. Marc has found a correlation between studying and performance on a final exam; whether or not it is significant would require the use of inferential statistics.

In an experiment, Sydney is going to investigate how alcohol affects aggression. The number of alcoholic drinks the subject has is called: (A) Controlled variable (B) Independent variable (C) Dependent variable (D) Experimental variable (E) Positive variable

(B) The independent variable in the experiment is the variable that is manipulated to test its effects on the other, dependent variables. In this experiment, the manipulation of the number of alcoholic drinks given to the subjects will affect their levels of aggression. The dependent variable in the experiment is measured to see how it is changed from the manipulation of the independent variable.

The Hawthorne effect is best defined as: (A) Expectations by the experimenter that can influence the results of an experiment (B) The change in the results of an experiment when it is "blind" versus "double blind" (C) The idea that people will alter their behavior because of the researchers' attention and not because of actual treatment (D) Specific, testable predictions derived from a theory (E) The idea that subjects in an experiment will lie if the researcher tells them to

(C) While researchers were testing the hypothesis that better lighting would boost worker output in an electric plant in the 1920s, they were surprised to see their results showed something else entirely. Productivity increased regardless of lighting merely because of the researcher's attention and not factory conditions. Choice (A) is incorrect because the Hawthorne effect focuses on the researcher's attention, not expectations. Choice (B) refers to the researcher's bias and change of behavior, not the subject's.

If a researcher is trying to establish a causal relationship between eating breakfast and work performance, the researcher should use which of the following methods of research? (A) Case study (B) Correlational research (C) Experimental research (D) Survey (E) Statistics

(C) With experimental research the strict control of variables offers the researcher the opportunity to draw conclusions about cause-and-effect relationships. In this instance, if the researcher wants to establish a causal relationship between eating breakfast and work performance, experimental research must be used. Correlational research does not allow the researcher to draw conclusions. Surveys simply allow the researcher to gather an immense amount of data in a short period of time.

Which of the following research methods does not permit researchers to draw conclusions regarding cause-and-effect relationships? (A) Experimental research (B) Surveys (C) Case studies (D) Correlational research (E) Naturalistic observations

(D) A correlation expresses a relationship between two variables without ascribing cause. Correlational research employs statistical methods to examine a relationship between two or more variables, but does not permit researchers to draw conclusions. Unlike correlational research, experimental research offers the opportunity to draw conclusions because of the strict control of variables.

Dr. Bisell conducts an experiment to see whether hunger makes mice run faster through a maze. He randomly assigns 25 mice to a control group or an experimental group. Which cannot be a confounding variable? (A) Where the experiment takes place (B) How hungry the mice were before the experiment (C) How fast the mice are before the race (D) When the experiment takes place (E) The population from which he selected the mice

(E) A confounding variable is anything that differs between the control group and the experimental group besides the independent variable. How fast and hungry the mice are at the beginning of the experiment are potential confounding variables. When and where the race takes place are also possible confounding variables that can potentially change the findings of this experiment. The population from which the mice were selected cannot be a confounding variable. This will not differ for the two groups. All of the mice were chosen from the same larger population. Even if this larger population is flawed, it is not considered a confounding variable.

Jordan runs an experiment testing the effects of sugar consumption on aggression levels in children. He randomly assigns 20 subjects either to a control group given sugar-free candy or to the experimental group that was given the same candy that did contain sugar. He then tests the subjects' response to several different puzzles, each with increasing difficulty. Jordan hypothesizes that sugar levels do play a role in aggression in children. In order to know whether his hypothesis has been supported, Jordan will need to use: (A) Descriptive statistics (B) Means-to-end statistics ( C) Experimental research (D) Scatter plots (E) Inferential statistics

(E) Jordan would need to use inferential statistics to determine whether the experimental group's aggression levels were significantly different. Jordan could very well use descriptive statistics, but not before he determines whether his hypothesis has been supported and represents the larger population.