2.1—principles of scientific research

Question 1

2.1 Learning Objectives

Answer 1

• know the key terminology related to the principles of scientific research.
• understand the five characteristics of quality scientific research.
  
  1. it is based on measurements that are objective, valid, and reliable.
  2. it can be generalized.
  3. it uses techniques that reduce bias.
  4. it is made public.
  5. it can be replicated.
  • objective, valid, and reliable measurements make it possible for other scientists to test whether they could come up with the same results if they followed the same procedures.
  • psychologists mostly study samples of individuals, but are usually more concerned about describing principles that generalize to a broader population.
  • single- and double-blind procedures are standard ways of reducing bias.
  • publishing results is what allows scientists to share information, evaluate hypotheses that have been confirmed or refuted, and replicate other researchers’ work.
• understand how biases might influence the outcome of a study.
  
  • demand characteristics affect how participants respond in research studies (e.g. trying to portray themselves in a positive light, even if it means not being truthful).
  • researchers can unintentionally influence their own studies.
• apply the concepts of reliability and validity to examples.
• analyze whether anecdotes, authority figures, and common sense are reliably truthful sources of information.

Question 2

2.1 Focus

Answer 2

• we hear claims from marketers and politicians every day, but how can we evaluate them?
• can we evaluate evidence even if we are not scientists?
• the most important aspect of scientific research is that it strives for objectivity: assuming that certain facts about the world can be observed and tested independently from the individual who describes them.
• subjective: when people’s knowledge of events is shaped by prior beliefs, expectations, experiences, and even mood.

Question 3

Five Characteristics of Quality Scientific Research

Answer 3

1. it is based on measurements that are objective, valid, and reliable.
2. it can be generalized.
3. it uses techniques that reduce bias.
4. it is made public.
5. it can be replicated.

Question 4

Objective Measurements

Answer 4

the measure of an entity or behaviour that, within an allowed margin of error, is consistent across instruments and observers.

Question 5

Variable

Answer 5

• variable: the object, concept, or event being measured.
• any method used by a researcher to measure a variable needs to include carefully defined terms.
• how would you define personality, shyness, or cognitive ability?
• in order to answer these questions, researchers must decide upon a precise definition that other researchers could understand (i.e. operational definitions).

Question 6

Operational Definitions

Answer 6

statements that describe the procedures (or operations) and specific measures that are used to record observations.

Question 7

Validity

Answer 7

the degree to which an instrument or procedure actually measures what it claims to measure.

Question 8

Reliability

Answer 8

• reliability: when a measure provides consistent and stable answers across multiple observations and points in time.
• test-retest reliability: examines whether scores on a given measure of behaviour are consistent across test sessions.
• alternate-forms reliability: examines whether different forms of the same test produce the same results.
• inter-rater reliability: when different observers have to rate a behaviour or response, and agree on the measurements that were taken.

Question 9

Generalizability

Answer 9

• generalizability: the degree to which one set of results can be applied to other situations, individuals, or events.
• one way to increase the possibility that research results will generalize is to study a large group of participants.
• we need to be careful to not over-generalize.

Question 10

Population

Answer 10

the ground that researchers want to generalize about.

Question 11

Sample

Answer 11

a select group of population members.

Question 12

Random Sample

Answer 12

a sampling technique in which every individual of a population has an equal chance of being included.

Question 13

Convenience Samples

Answer 13

samples of individuals who are the most readily available.

Question 14

Ecological Validity

Answer 14

the results of a laboratory study can be applied to or repeated in the natural environment.

Question 15

Researcher and Subject Biases

Answer 15

• researcher bias: when various types of bias are unintentionally introduced by the researchers.
• subject biases or participant biases can also manipulate the experiment.
• the issue of bias in research is difficult to overcome; few researchers intentionally manipulate their participants.
• in most cases, experimenters complete rigorous training and follow careful scripts when explaining experimental procedures to participants.
• manipulating participants’ expectations of the results and then evaluating whether or not this influences the outcome is helpful, but can be unethical.

Question 16

Hawthorne Effect | Biases

Answer 16

• Hawthorne effect: a behaviour that occurs as a result of being observed.
• in the 1920s, researchers went to Western Electric Company’s Hawthorne works to study the relationship between productivity and working conditions.
• researchers noted that different lighting and break times improved productivity.
• but the researchers didn’t notice was that any small change increased productivity.
• workers were working harder because they noticed they were being watched.

Question 17

Demand Characteristics | Biases

Answer 17

• demand characteristics: inadvertent cues given off by the experimenter or the experimental context that provide information about how participants are expected to behave.
• this can be explained by the fact that, when given no explanation, people will draw their own conclusions.
  
  • e.g. the backpack experiment; people wearing backpacks for a week were asked to judge the steepness of a ramp.
• researchers and observers can also introduce biases and unwittingly draw out the responses they desire.
  
  • e.g. Rosenthal and colleagues; teachers were told that certain students (randomly chosen) had an “unusual” potential for learning and those students ended up doing better.

Question 18

Social Desirability

Answer 18

when research participants respond in ways that increase the chances that they will be viewed favorably.

Question 19

Anonymity and Confidentiality

Answer 19

• anonymity: when each individual’s responses are recorded without any name or other personal information that could link a particular individual to specific results.
• confidentiality: the results will be seen only by the researcher.

Question 20

Placebo Effect

Answer 20

a measurable and experienced improvement in health or behaviour that cannot be attributable to a medication or treatment.

Question 21

Single-Blind Study

Answer 21

the participants do not know the true purpose of the study, or else do not know which type of treatment they are receiving (for example, a placebo or a drug).

Question 22

Double-Blind Study

Answer 22

• double-blind study: a study in which neither the participant nor the experimenter knows the exact treatment for any individual.
• also used when researchers are testing groups that differ on variables such as personality characteristics or subtle demographic factors such as sexual orientation.

Question 23

Peer Review

Answer 23

• peer review: a process in which papers submitted for publication in scholarly journals are read and critiqued by experts in the specific field of study.
• in psychology, peer review requires two main tasks.
• first, an editor receives the manuscript from the researcher and determines whether it’s appropriate subject matter for the journal.
• second, the editor sends copies of the manuscript to a select group of peer reviewers (other professionals working within the same field of study).
• peer reviewers critique the methods and results of the research and make recommendations to the editor regarding the merits of the research.

Question 24

Replication

Answer 24

the process of repeating a study and finding a similar outcome each time.

Question 25

Five Characteristics of Poor Research

Answer 25

poor evidence most often comes in one of five varieties: untestable hypotheses, anecdotes, a biased selection of available data, appeals to authority, and appeals to (so-called) common sense.

Question 26

Fasifiable

Answer 26

• falsifiable: the hypothesis is precise enough that it could be proven false.
• for a hypothesis to be testable, it must be falsifiable.
• if a hypothesis is not falsifiable, that means that there is no pattern of data that could possibly prove that this view is wrong.

Question 27

Anecdotal Evidence

Answer 27

• anecdotal evidence: an individual’s story or testimony about an observation or event that is used to make a claim as evidence.
• for example, if a man claims he lost 50 pounds in six months using CDs, there’s no way to know if the weight loss is a result of listening to the CDs.
• data selection bias: presenting only data that supports a person’s views.

Question 28

Appeal to Authority

Answer 28

• appeal to authority: the belief in an “expert’s” claim even when no supporting data or scientific evidence is present.
• expertise is not actually evidence; “expert” describes the person making the claim, not the claim itself.

Question 29

Appeal to Common Sense

Answer 29

• appeal to common sense: a claim that appears to be sound, but lacks supporting scientific evidence.
• appeals to tradition, i.e. “We’ve always done it this way!”
• appeals to novelty, i.e. “It’s the latest thing!”