DISCUSSION 2 PBI 1 & 2

THE EXPERIMENTAL METHOD

As we know that experiment is one of the way in which research that can or should be conducted. Therefore, we have to know what is the mean of experiment? What is the method of experiment? Why experiments?

Generally speaking, experiments are carried out in order to explore  the strength of relationships between variables. A variable as the term itself suggests, is anything which  does not remain constant. In such a case it is customary to distinguish between the two variables by giving them different labels. The label given to the variable that the experimenter expects  to influence the other is called the independent variable(teaching method), while the variable upon which the independent variable is acting is called the dependent variable(the test course). An experiment is a controlled look a nature. The experimenter set up a taks in which the structure of the task is explicit, the nature of the performance being studied is explicit, and the question that is being asked is precise (Paivio and Begg, quoted by Cook,1986 : 13).

Doing experiment, certainly we talk about data or evidence, and there are many ways or method that can we use in collect them such as we can use statistic to help us gathering data from the subject. From statistical point of view when studying numerical data of various sorts, the two things we will be most interested in are extent to which data are similar and the degree to which the data differ. The most frequently employed measure of similarity is the mean, which is simply the average of a set of scores ( obtained by adding  the individual scores together and dividing by the total of number of scores), it gives us an information about the central tendency of the scores.

Standard Deviation (SD) on other hand is the most important measure of dispersion, giving us an information on the extent to which a set scores varies in relation to the mean, it is calculated by deducting the mean from each individual score, squaring the resulting figures to get rid of the minus signs, adding these together, and dividing by the number of sores minus one ( Dividing by one less than the number of scores is a correction for the fact that the variability of scores for a single group of subjects tends to be less than the variability for all possible scores). This gives us the variance, In addition, statistic is the most  important thing when we doing an experiment.

Data-gathering itself need not involve a long, protracted period of time; the relationship between the data sets gathered, their numerical analysis, and the research question is decided in advance; the interpretation of the results depends on features of the experiment which are also  decided in advance. Therefore, if a teacher wants answer to precise-enough questions and has the power to manipulate  the learning context to design an appropriate experiment, there is sense in doing so.

Brown (1988), in particular, has argued that, while it  is unlikely  that teachers will want or be able to get involved in experimentation (except as subjects themselves),  a knowledge  of how experiments are designed and conducted gives them access to valuable literature which is difficult without such prior knowledge. 

Much research in education today conforms to a design in which a single group is studied only once, subsequent to some agent or treatment presumed to cause change. But we have to realize, it is not rigorous enough to allow to claim that there is causal relationship between the independent variable and the dependent variable because there is always the possibility that some factors other than the experimental materials has brought about the observed  differences in the score.  

In doing research in which the data are obtained from formal experiments, it is usually only feasible to test a sample of the population, for reasons out lined earlier. The problem for researcher is to decide whether the data obtained from the sample are representative of the population as a whole. There are three types of experiment they are pre-experiment, quasi experiment and true experiment. pre experiment is the simplest form of research design. Quasi experiment is an empirical study used to estimate the causal impact of an intervention on its target population without random assignment. True experiment is a type of experimental design and is thought to be the most accurate type of experimental research.

Experiments are designed to answer precise questions. Therefore,  an experiment needs:  a precise question, an explicit set of variables, an explicit task which can be measured (at whatever level  of measurement), sufficient participants  to enable statistical inferences  to be made, controls and counterbalances to eliminate rival interpretation and a means of ensuring  the relevance of the results to the question.

Questions :

1. What is the influence of giving the experimental method to the student? 

2. Why are the experiment and quasi experiment important in language learning research tools?