Research Methods and Ethical Considerations

True experiment

Goal: to establish a cause and effect relationship between two variables

Essential characteristics:

• Independent variable (IV) manipulated by researcher

• Dependent variable (DV) measured by researcher

• Control of other (extraneous) variables (to increase internal validity)

• IV and DV operationalized (written in a measurable way)

• Standardized procedures

• Random allocation of participants to conditions (even if participants were not chosen randomly)

• The data is statistically analyzed and a p-value is calculated.

Quasi Experiment

• The IV is not manipulated by the researcher.

• Causality cannot be determined.

• There is an attempt to control extraneous variables, increasing internal validity.

• Participants are not randomly allocated to conditions. They are assigned based on a pre-existing participant variable. 

• The data is statistically analyzed and a p-value is calculated.

Natural Experiment

• An independent variable is naturally occurring - that is, it is not manipulated by the researcher -  and a dependent variable is measured. Causality cannot be determined.

• It is not really possible to control for extraneous variables; matching designs are used to determine the influence of some participant variables.

• Participants are not randomly allocated to conditions.

• The data is statistically analyzed and a p-value is calculated.

Research Hypothesis

A research hypothesis (or experimental hypothesis) predicts the relationship between the independent variable (IV) and the dependent variable (DV). When we manipulate the IV, what will happen to the DV?

Null Hypothesis

In experimental research, we formulate both a null hypothesis and an experimental hypothesis. The null hypothesis states that the IV will have no effect on the DV, or that any change in the DV will be due to chance.

Quantitative Research (#)

• researchers measure the effect of an independent variable on a dependent variable in order to test a hypothesis. They try to establish cause and effect. They try to characterize the behavior of large groups of people.

  • The actual experience of the participants is often not seen as important.

Qualitative Research (Words)

• Qualitative researchers are concerned with meaning - that is, they are interested in how people make sense of the world and how they experience events. 

  • How do people work in teams in the workplace? How do women deal with postpartum depression? How do IB students cope with stress?

• Often trying to solve the problems that the research identifies. 

Case Study

• Case studies are very common in psychology

• Not really a method by itself, but a mix of several (method triangulation)

  • Interviews, observations, experiments, brain imaging technologies

• Holistic

• Often longitudinal - may study the person for months or years

• individual or family or small group

• Often (but not always) a unique case that cannot be replicated

Repeated Measures

In a repeated measures design, you have one sample of participants that receives both conditions of an experiment.  If we were testing the effect of music on learning, the same participants would memorize a list of words with music - and then again without music.

Strength of this design: 

• participant variability is controlled because each individual is compared to him or herself

Limitations of this design: 

• order effects - Because participants take part in more than one condition, they may get worse due to boredom or fatigue, or they may get better due to practice 

• Demand characteristics - participants may figure out the experiment’s purpose and try to help (expectancy effect) or hurt (screw you effect) the results

• Often the same materials may not be used for both conditions, so there is a confounding (or extraneous) variable introduced - the difficulty level of the word lists may be different

Control to help limit order effects: counter-balancing (one group does condition A then B; other group does condition B then A)

Independent Sample Design

In an independent samples design, the sample is randomly allocated to one of the conditions of the experiment. If we were testing the effect of music on learning, the participants would be randomly assigned to the classical music, rock music, pop music or no music condition.

So there is one group of participants in the music condition and a completely different group of participants in the no music condition.

Strength of this design: 

• Controls for all the limitations of repeated measures: 

  • order effects

  • demand characteristics

  • confounding variable of different materials

Limitation of this design: 

• participant variability - one group may have stronger memories than the other

Control to help limit participant variability: matched pairs design

Matched Pairs

A matched pairs design is an independent samples design in which participants are not randomly allocated to conditions. Instead, they are usually pre-tested with regard to the variable.

 

So, a memory test may be given and then the weakest memorizers are randomly allocated to one of the conditions, then the middle performing memorizers are allocated and then the top performing memorizers. (Basically this is a way of ensuring that the teams are fair.)

Protection From Harm

 It is important to make sure that no harm is done to participants. It is not permitted to humiliate a participant or force them to reveal private information. And it is important that there is nothing done to the participant that will have a permanent effect on their physical or psychological health. 

Notice that psychologists use the term "undue" stress or harm.  Health psychologists study stress - so, how would we study stress if we cannot cause stress in a participant?  "Undue" stress is a higher level of stress than an individual may experience on a day to day basis.  Asking participants to solve a frustrating puzzle before being asked to memorizing a list of words is not an example of "undue" stress or harm.

Due to the nature of qualitative methods participants may disclose very private information that they have never shared with anyone before. This is particularly true in sensitive research topics, such as sexual abuse, domestic violence, or alcoholism in the family. The researcher should not apply undue pressure on an individual to disclose something that they do not wish to share. After the interview, the participant may have second thoughts and wish to withdraw that information. This must be respected by the researcher.

Informed Consent

• Psychologists must obtain informed consent from participants before the research begins. Participants must agree to participate. The researcher must provide the participants with sufficient information about the study, such as who funded the study, who will conduct the study, how the data will be used, and what the research requires of the participants.

• They must also be told what rights they have, including the right to withdraw from the study at any time.   

• In biological research, this is often complicated as many people do not really understand genetic or biochemical terminology.  

• In cases where children aged under 16 years are involved, consent must be obtained from parents or legal guardians.

• In addition, people with mental or physical illness may not be able to really understand the implications of agreeing to take part in a study.  In this case, it is often guardians that give consent for their family member. 

• In some cases, where it would not otherwise be possible to study a phenomenon (e.g. use of violence in a street gang), ethics committees may allow exemption from the rule.

Use of Deception

• If the psychologist tells you what she is studying, this may influence your behavior.  In order to prevent this, researchers may use deception. 

• Deception can either be misinformation or it may be not telling the participant the complete goal of the study.  

• Deception should generally not be used; however, slight deception, which does not cause any stress to the participant, may be used in some cases.   

• However, before deception may be used, the psychologist proposing the study must justify why it is necessary and an ethics board should approve the study.

Right to Withdraw

• A participant has the right to withdraw from a study at any time. 

• If they wish to withdraw from the study, they should feel no pressure or coercion from the psychologist to remain.

• Their data must be withdrawn from the study if they request it.

Anonymity and Confidentiality

• Confidentiality 

  • means that research data will not be known to anyone outside the study. The researcher may have to change minor details in the report to avoid the possibility of participants being recognized.

  • Focus groups are problematic in that it is difficult to guarantee confidentiality as the members of the focus group may - either intentionally or unintentionally - reveal information that was shared in confidentiality in the study.

• Anonymity 

  • relates to the way data are stored after the research. If interviews or observations have been videotaped, it can be difficult to guarantee total anonymity, so these should be destroyed when transcripts have been made. If the researcher finds it necessary to archive non-anonymized data, the participant should give written informed consent.

  • The identity of the participants should not be known outside the research team, but in cases where sampling has involved a third party (e.g. managers, friends, teachers), this cannot be done, and in this case, the participants should be informed. 

Debriefing

• At the end of the study, all participants must be debriefed.  

• In a debriefing, the true aims and purpose of the research must be revealed to the participants. Any deception must be justified. 

• Results of the study are shared with participants if possible.

• All participants should leave the study in the same physical and psychological state in which they arrived.