In Which Of The Following Ways Are Conducting Research With Humans Versus Animals Different?

Chapter 6: Experimental Research

Conducting Experiments

1. Describe several strategies for recruiting participants for an experiment.
2. Explain why it is important to standardize the procedure of an experiment and several ways to do this.
3. Explain what pilot testing is and why it is important.

The data presented then far in this chapter is enough to design a bones experiment. When it comes fourth dimension to conduct that experiment, however, several additional practical issues arise. In this section, nosotros consider some of these issues and how to deal with them. Much of this information applies to nonexperimental studies as well as experimental ones.

Recruiting Participants

Of course,at the first of whatever research projectyou lot should exist thinking well-nigh how you will obtain your participants. Unless you lot have access to people with schizophrenia or incarcerated juvenile offenders, for example, and so there is no point designing a written report that focuses on these populations. But even if you plan to use a convenience sample, you will have to recruit participants for your written report.

There are several approaches to recruiting participants. 1 is to use participants from a formal —an established group of people who have agreed to be contacted about participating in research studies. For example, at many colleges and universities, at that place is a subject puddle consisting of students enrolled in introductory psychology courses who must participate in a sure number of studies to meet a grade requirement. Researchers post descriptions of their studies and students sign up to participate, usually via an online system. Participants who are not in bailiwick pools tin can also exist recruited by posting or publishing advertisements or making personal appeals to groups that stand for the population of interest. For case, a researcher interested in studying older adults could arrange to speak at a coming together of the residents at a retirement community to explain the report and ask for volunteers.

"Report."The poster reads: Volunteers needed for a scientific written report investigating whether people can distinguish between scientific studies and kidney-harvesting scams. (Healthy Blazon-O Adults Just).

Fifty-fifty if the participants in a written report receive bounty in the class of grade credit, a small corporeality of money, or a gamble at being treated for a psychological problem, they are yet essentially volunteers. This is worth considering because people who volunteer to participate in psychological research accept been shown to differ in predictable ways from those who do not volunteer. Specifically, at that place is skilful evidence that on average, volunteers have the following characteristics compared with nonvolunteers (Rosenthal & Rosnow, 1976)^[1]:

• They are more interested in the topic of the inquiry.
• They are more educated.
• They accept a greater need for approving.
• They have higher intelligence quotients (IQs).
• They are more than sociable.
• They are college in social class.

This divergence can be an result of external validity if at that place is reason to believe that participants with these characteristics are likely to bear differently than the general population. For example, in testing different methods of persuading people, a rational argument might piece of work better on volunteers than it does on the general population because of their more often than not college educational level and IQ.

In many field experiments, the chore is not recruiting participants but selecting them. For case, researchers Nicolas Guéguen and Marie-Agnès de Gail conducted a field experiment on the effect of being smiled at on helping, in which the participants were shoppers at a supermarket. A confederate walking downwardly a stairway gazed straight at a shopper walking up the stairway and either smiled or did not grin. Soon afterward, the shopper encountered another amalgamated, who dropped some calculator diskettes on the footing. The dependent variable was whether or not the shopper stopped to assistance pick up the diskettes (Guéguen & de Gail, 2003) ^[2]. Detect that these participants were not "recruited," but the researchers still had to select them from among all the shoppers taking the stairs that 24-hour interval. It is extremely of import that this kind of choice exist done according to a well-defined gear up of rules that is established before the data collection begins and tin can exist explained clearly afterward. In this case, with each trip downwardly the stairs, the confederate was instructed to gaze at the showtime person he encountered who appeared to be between the ages of 20 and 50. But if the person gazed back did he or she become a participant in the study. The point of having a well-defined option rule is to avoid bias in the selection of participants. For example, if the amalgamated was gratis to choose which shoppers he would gaze at, he might choose friendly-looking shoppers when he was fix to smile and unfriendly-looking ones when he was non set to smile. Every bit nosotros will run into shortly, such biases can be entirely unintentional.

Standardizing the Procedure

Information technology is surprisingly easy to introduce inapplicable variables during the procedure. For example, the same experimenter might give clear instructions to one participant just vague instructions to some other. Or 1 experimenter might greet participants warmly while some other barely makes middle contact with them. To the extent that such variables affect participants' behaviour, they add noise to the data and make the effect of the independent variable more difficult to observe. If they vary beyond conditions, they get misreckoning variables and provide alternative explanations for the results. For example, if participants in a treatment group are tested past a warm and friendly experimenter and participants in a control group are tested by a cold and unfriendly 1, so what appears to be an effect of the handling might actually be an result of experimenter demeanor. When there are multiple experimenters, the possibility for introducing extraneous variables is even greater, simply is often necessary for practical reasons.

It is well known that whether inquiry participants are male or female tin can affect the results of a study. But what nearly whether the experimenter  is male or female? At that place is plenty of show that this matters too. Male person and female experimenters accept slightly different ways of interacting with their participants, and of course participants too respond differently to male and female person experimenters (Rosenthal, 1976) ^[three].

For example, in a recent study on pain perception, participants immersed their hands in icy water for every bit long as they could (Ibolya, Brake, & Voss, 2004) ^[4]. Male participants tolerated the pain longer when the experimenter was a woman, and female participants tolerated information technology longer when the experimenter was a man.

Researcher Robert Rosenthal has spent much of his career showing that this kind of unintended variation in the process does, in fact, affect participants' behaviour. Furthermore, one important source of such variation is the experimenter's expectations about how participants "should" conduct in the experiment. This outcome is referred to as an  (Rosenthal, 1976) ^[5].For case, if an experimenter expects participants in a treatment group to perform improve on a task than participants in a command group, and so he or she might unintentionally requite the handling group participants clearer instructions or more encouragement or allow them more time to complete the job. In a striking example, Rosenthal and Kermit Fode had several students in a laboratory course in psychology train rats to run through a maze. Although the rats were genetically similar, some of the students were told that they were working with "maze-bright" rats that had been bred to be adept learners, and other students were told that they were working with "maze-dull" rats that had been bred to be poor learners. Certain enough, over v days of training, the "maze-bright" rats made more than right responses, fabricated the correct response more chop-chop, and improved more steadily than the "maze-dull" rats (Rosenthal & Fode, 1963) ^[vi]. Clearly it had to take been the students' expectations about how the rats would perform that made the divergence. Merely how? Some clues come from data gathered at the end of the study, which showed that students who expected their rats to larn speedily felt more than positively well-nigh their animals and reported behaving toward them in a more friendly manner (e.g., handling them more).

The way to minimize unintended variation in the procedure is to standardize information technology as much as possible so that it is carried out in the aforementioned way for all participants regardless of the status they are in. Here are several ways to do this:

• Create a written protocol that specifies everything that the experimenters are to exercise and say from the time they greet participants to the time they dismiss them.
• Create standard instructions that participants read themselves or that are read to them word for give-and-take by the experimenter.
• Automate the balance of the process equally much as possible past using software packages for this purpose or even simple computer slide shows.
• Anticipate participants' questions and either raise and answer them in the instructions or develop standard answers for them.
• Railroad train multiple experimenters on the protocol together and have them exercise on each other.
• Be certain that each experimenter tests participants in all conditions.

Another good do is to accommodate for the experimenters to be "blind" to the research question or to the condition that each participant is tested in. The thought is to minimize experimenter expectancy furnishings past minimizing the experimenters' expectations. For example, in a drug report in which each participant receives the drug or a placebo, it is often the instance that neither the participants nor the experimenter who interacts with the participants know which condition he or she has been assigned to. Because both the participants and the experimenters are blind to the status, this technique is referred to as a . (A single-blind written report is one in which the participant, but not the experimenter, is blind to the status.) Of course, there are many times this blinding is not possible. For example, if you are both the investigator and the just experimenter, information technology is non possible for you to remain bullheaded to the research question. Also, in many studies the experimenter must  know the status because he or she must carry out the procedure in a different style in the different weather.

Placebo effect blocker. [Prototype Description]

Record Keeping

Information technology is essential to keep skillful records when you lot comport an experiment. As discussed earlier, it is typical for experimenters to generate a written sequence of conditions before the study begins and then to test each new participant in the next status in the sequence. As you test them, it is a proficient idea to add to this list basic demographic information; the date, time, and identify of testing; and the name of the experimenter who did the testing. It is also a skilful idea to have a place for the experimenter to write downward comments about unusual occurrences (eastward.g., a dislocated or uncooperative participant) or questions that come. This kind of information tin can be useful later if you decide to analy z e sex differences or effects of different experimenters, or if a question arises about a particular participant or testing session.

It can likewise be useful to assign an identification number to each participant as yous examination them. Merely numbering them consecutively beginning with 1 is usually sufficient. This number can then besides exist written on whatsoever response sheets or questionnaires that participants generate, making it easier to go on them together.

Pilot Testing

Information technology is always a good thought to bear a  of your experiment. A pilot test is a small-scale study conducted to brand sure that a new procedure works every bit planned. In a pilot examination, you can recruit participants formally (e.g., from an established participant pool) or you tin can recruit them informally from among family unit, friends, classmates, and then on. The number of participants tin can exist small, but it should be enough to give you conviction that your procedure works equally planned. There are several important questions that you can answer past conducting a pilot test:

• Practise participants understand the instructions?
• What kind of misunderstandings do participants have, what kind of mistakes practise they make, and what kind of questions do they inquire?
• Exercise participants get bored or frustrated?
• Is an indirect manipulation effective? (You will need to include a manipulation bank check.)
• Can participants estimate the research question or hypothesis?
• How long does the procedure take?
• Are calculator programs or other automatic procedures working properly?
• Are information being recorded correctly?

Of course, to respond some of these questions you lot will need to notice participants carefully during the procedure and talk with them about it afterward. Participants are often hesitant to criticize a study in front of the researcher, so be sure they understand that their participation is part of a pilot exam and you are genuinely interested in feedback that will help you improve the procedure. If the procedure works as planned, and so y'all can go on with the actual report. If at that place are problems to be solved, you tin solve them, pilot test the new procedure, and continue with this process until you are gear up to proceed.

• There are several effective methods you tin use to recruit research participants for your experiment, including through formal discipline pools, advertisements, and personal appeals. Field experiments require well-divers participant choice procedures.
• It is important to standardize experimental procedures to minimize extraneous variables, including experimenter expectancy effects.
• Information technology is important to conduct one or more small-scale pilot tests of an experiment to be sure that the process works as planned.

1. Practice: List ii ways that you might recruit participants from each of the following populations:
   1. elderly adults
   2. unemployed people
   3. regular exercisers
   4. math majors
2. Discussion: Imagine a study in which you lot volition visually present participants with a list of 20 words, one at a time, wait for a short fourth dimension, and then ask them to recall as many of the words as they can. In the stressed condition, they are told that they might also be chosen to give a short speech communication in forepart of a small audience. In the unstressed status, they are non told that they might accept to give a speech. What are several specific things that yous could do to standardize the procedure?

Paradigm Descriptions

A comic of 2 stick figures talking.

Person ane: Some researchers are starting to figure out the mechanism behind the placebo issue. Nosotros've used their piece of work to create a new drug: A placebo effect blocker. Now nosotros just need to run a trial. We'll get 2 groups, give them both placebos, and then give one the REAL placebo blocker, and the other a…. wait.

[The ii people scratch their heads]

Person ii: My head hurts.

Person i: Mine too. Here, want a sugar pill?

[Return to Image]

Media Attributions

• Study by XKCD CC Past-NC (Attribution NonCommercial)
• Placebo blocker past XKCD CC By-NC (Attribution NonCommercial)

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Source: https://opentextbc.ca/researchmethods/chapter/conducting-experiments/

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