The introduction provides background information, as well as a rationale for the investigation. It is important that this section of the paper clearly sets out what you are going to investigate, and why the investigation is important.
The introduction is an important part of your report. In addition to describing the study that you are going to replicate, it also helps the reader understand the importance of this study and the theory upon which it is based. When thinking about writing this section, you should try to explain this as if you are explaining it someone how has never studied this area of human behaviour before. Don't make assumptions about what the reader knows about your topic.
The introduction includes the following information:
- A general introduction to the psychological question under investigation.
- A description of the theory or model upon which the study is based and an explanation of how the theory or model link to your own experiment.
- Definition of any terminology necessary for understanding your study.
- A description of the study that you are replicating.
- A statement of the aim of your study and an explanation of its relevance. Why is this an important area of investigation?
- The introduction should end with a statement of the null and research hypotheses specific to your study —that is, a clear prediction of what you expect to find through your investigation. The independent and dependent variables should be fully operationalized in the hypotheses.
The introduction should focus on the theory or model that is investigated and this should include details of the study that is being replicated and how that study investigated the theory or model. The study to be replicated should be described in terms of its the aim, procedure, findings, and conclusions. You will need this to make comparisons of your own results to those of the original study in the final section of the report.
After explaining the original experiment, you should state why you think the theory or model of the original study is important to investigate, which is also explains why the study could be worth replicating. What value does this research have in our understanding of human behaviour? You should finalize your introduction by clearly stating the aim of your research. For example:
- Aim: to investigate the effects of particular adjectives on the formation of impressions in bilingual high school students.
- Aim: to investigate the effect of leading questions on estimation of speed in a car accident in 18-year-old American students with driving experience.
The introduction should then end with a clear statement of the investigation’s null and research hypotheses. The variables in the hypotheses must be clearly operationalized – and any modifications made to the original study should be justified.
Research and null hypotheses
In experimental research, psychologists first must state what they predict will happen. To do this, we state a null and a research hypothesis.
The null hypothesis states that there will be no effect of the manipulation of the independent variable on the dependent variable -in other words, the null hypothesis states that any difference found is due to chance and not the manipulation of the independent variable. In fact, it is the null hypothesis that is tested as a researcher normally wants this to be refuted.
The research hypothesis predicts how the independent variable is expected to affect the dependent variable. Simply stating that the independent variable will affect the dependent variable is not enough; the actual effect should be clearly predicted.
A well-written hypothesis is clearly operationalized. This means that the IV and DV are stated in a way that is measurable. Simply stating that “Noise will have an effect on learning” is not an operationalized hypothesis. What is meant by “noise?” How are you going to measure “learning?” An operationalized hypothesis for this study might be: Participants who listen to classical music while reading a description of a new school (IV) will be able to recognize more details about the school from a list of statements (DV) than students who read the text in silence.
The aim was to investigate whether there is a higher recall of words using the method of loci in free recall than using no memory technique.
The null hypothesis for this experiment would be There will be no significant difference in the number of details about a school that a participants will recognize from a list of statements when listening to classical music or under silent conditions.
Remember that the goal of research is not to prove the research hypothesis correct, but to refute the null hypothesis. In other words, we want to establish that there actually is a relationship between the IV and the DV, and that any results we have obtained were not just due to chance. When we can statistically establish that the results are not due to chance, the data are significant. When the data are significant, we refute the null hypothesis. When our data are not significant, we retain the null hypothesis. This simply means that the IV did not cause changes in the DV.
Cognitive psychologists argue that we are cognitive misers – that is, “humans, valuing their mental processing resources, find different ways to save time and effort when negotiating the social world (Fiske & Harris, p 2).” One of the ways in which we do this is by using heuristics. Heuristics can be defined as “judgmental shortcuts that generally get us where we need to go – and quickly – but at the cost of occasionally sending us off course (Gilovich & Savitsky, p 34). ”
One of these heuristics, which helps us to make quick decisions about information, is called anchoring bias. Anchoring bias is defined as the common human tendency to rely too heavily, or "anchor," on one trait or piece of information when making decisions (Anchoring bias). Anchoring often happens because there is not enough information for the individual to make a decision, so the initial information provided serves as a basis for making further decisions. This can have serious implications. For example, Englich & Mussweiler (2001) found that anchoring bias plays a significant role in determining sentencing in courtrooms. When told that the maximum sentence was 34 months, jurors recommended on average eight months longer in prison that when told that the maximum sentence was 12 months – for the same crime. In this case, the juror would not have a lot of experience in making these decisions, so the maximum sentence as stated by the judge would then influence the decision for how long the accused should be in prison.
One of the original studies on anchoring bias was done by Tversky & Kahnemann (1974). In this study, high school students were used as participants. Participants in the “ascending condition” were asked to quickly estimate the value of 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8. Those in the “descending condition” were asked to quickly estimate the value of 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1. Since we read from left to right, the researchers assumed that group 1 would use "1" as an anchor and predict a lower value that the group that started with "8" as the anchor. The expectation was that the first number seen would bias the estimate of the value by the participant. The researchers found that the median for the ascending group was 512; the median for the descending group was 2250. The actual value is 40320.
Based on this study, the aim of our investigation is to see if anchoring bias plays a role in mathematical estimation among international high school students. Teachers of mathematics often ask students if they think that their answers look reasonable. It is possible that anchoring bias would affect this. So, we decided to use IB HL mathematics students for this study so that we could eliminate the confounding variable of weak mathematics skills.
Null hypothesis: There will be no significant difference in the responses given by IB higher level math students when asked to estimate the value of 8! when the problem is presented in either ascending or descending order.
Research hypothesis: IB higher level math students will estimate a higher value for 8! when the problem is presented in descending order vs. in ascending order.
Anchoring bias in decision-making, Science Daily, retrieved February 28, 2016. Available at: https://www.sciencedaily.com/terms/anchoring.htm
Englich, B., & Mussweiler, T. (2001). Sentencing under uncertainty: Anchoring effects in the courtroom. Journal of Applied Social Psychology, 31, 1535–1551.
Fiske, S.T., & Taylor, S.E. (1991). Social Cognition (2nd ed.). New York: McGraw Hill.
Gilovich, T. & Savitsky, K. (1996). Like goes with like: The role of representativeness in erroneous and pseudoscientific beliefs. Skeptical Inquirer.
Tversky, A.; Kahneman, D. (1974). "Judgment under Uncertainty: Heuristics and Biases". Science 185 (4157): 1124–1131.
Comments on the introduction
Paragraph 1: Notice that important terms are defined and the definitions are cited. Don't just make up a definition, use what is recognized by psychologists as an "official definition" of the terms.
Paragraph 2: The theory is described and its importance is explained using an example.
Paragraph 3: The study to be replicated is identified and correctly cited. The procedure of the study is not only described, but its rationale is explained. There is a clear statement of the original results that will allow for later comparison in the evaluation section of the report.
Paragraph 4: The aim of the study is clearly stated with reference to the population to be studied. The rationale for both the study and the choice of sample is clearly explained.
How you are assessed
The following table is the assessment rubric used to award marks for your introduction.