Читать книгу Introduction to Experimental Linguistics - Sandrine Zufferey - Страница 15

To attenuate these potential problems, and to reduce the importance of the characteristics of the participants or the material employed, experimental research is based on data collected from a large number of people, using a broad palette of materials. Referring back to our example, it would be necessary to test a large number of people by means of a comprehension test. This test should contain multiple texts and different questions for each of them. In general, the material used in an experiment is defined as a set of items (the texts or the questions in our example are items). The ideal number of participants, as well as the number of items necessary to undertake proper research, is a complex question, which we will address in Chapter 6.

Furthermore, experimental research is generally carried out by recruiting naive participants, who ignore the goals of the experiment and who have zero expertise in the subject under study. This precaution aims to try to control certain cognitive biases that could influence research results. The first bias is related to the fact that the participants who know the research hypothesis may try to base their answers on this hypothesis. Should this happen, the results obtained could suffer from what is called confirmation bias. Rather than answering naturally, participants could provide answers based on the hypothesis to confirm it, not because the assumption is correct, but rather because it seems adequate to them (even if this is not the case). The second bias is related to the fact that participants may want to help the researcher. If the participants know or suspect the goal of an experiment beforehand, the results obtained in this second scenario may not correspond to reality, but rather to the answers that the participants presume are expected.

Finally, in experimental research, participants are generally assigned to conditions in a random manner. This means that every person has the same chances of being included under one condition of the experiment or another. This random assignment offers additional protection against the effect of uncontrolled external variables. In addition to testing a large number of people, randomly distributing them to the different conditions reduces the probability that external variables could systematically influence the results. However, this random assignment is only feasible when all variables are manipulated. When one or more variables are simply observed, participants must be included in one condition or another on the basis of their own characteristics, such as gender or age, for instance. In this case, we speak of quasi-experimental research, since it is not possible to control all the variables. Leaving this question aside, experimental and quasi-experimental research is very similar, and the elements developed in the following chapters apply to both types of research.