In the current psychological research, in addition to qualitative researchers, few people really use pure empirical method - although many people claim to use this method. It is very difficult for people to just record the observed situation in the research, and people often inevitably have to ask: "why does this happen?" In fact, before people begin to observe, they may ask such questions - people do not observe calmly, but they will bring questions and ask questions when they observe.

In fact, more psychological research is to test scientific theory, using the hypothesis deductive method. The name of this method is a little cumbersome. We usually don't use this term, but use empirical method to replace it - of course, such a simple replacement is not accurate, or even inappropriate. There are six steps in the hypothetical deductive method: first, observe, collect and sort out the data; The second step is to induce and get laws from data; The third step is to form a theory to explain the law; The fourth step is to deduce and put forward the hypothesis of test theory; The fifth step is to test, form research forecast and test hypothesis; Step 6: get the results and test whether the research results support the theory or challenge the theory (coolican, 2014).

Obviously, the first two steps of hypothetical deductive method are empirical method. In short, the hypothetical deductive method is a scientific method to evaluate theory by putting forward and testing hypotheses. Theory is the general explanation of the law or law obtained from observation; Hypothesis is a statement about the world derived from general theory. This method is illustrated by the study of short-term memory and long-term memory.

Step 1: Test short-term memory with word lists of different lengths.

Step 2: when the subjects were presented with a list of 20 words and were allowed to recall freely after the list was presented, the subjects recalled the last four or five words better and found the proximate effect.

The third step is to put forward the theory of long-term memory / short-term memory, which shows that human beings have a short-term memory and a long-term memory, and the items in the word list need to be repeated in the short-term memory buffer to enter the long-term memory.

Step 4: if the item retelling in the buffer is true, then when people are asked to recall a word list, they need to clear the buffer first, so the proximate effect occurs. It is assumed that the proximate effect is caused by the early emptying of the retelling buffer.

In step 5, the subjects were asked to recall a word list as freely as possible. In order to prevent them from repeating, they were asked to do an interference task unrelated to the memory task within 30 seconds after the word list was presented.

Step 6: if the recency effect disappears, the retelling buffer emptying hypothesis is supported, and the general short-term memory / long-term memory theory is supported. If the proximate effect does not disappear, then we need to put forward other explanations for the proximate effect.

If the researchers did the above experiments, what would it mean if the proximate effect disappeared? Can this prove that the proximate effect is caused by the initial buffer emptying? No, in Psychology (and other sciences), there's no need to say "prove.". Why not? Because there is always some other explanation for any research result. For example, what other explanation is there for the disappearance of proximate effect here? In this specific experiment, the last words in the list may be more difficult to recall than other words. There are many ways to deal with this problem and then do another experiment. For example, researchers can do a pre experiment with other subjects to ensure that all words are recalled to the same degree. Another possible explanation is that the interference task is not related to memorizing word lists as originally thought. Maybe it's the interference task that causes the forgetting of words - I didn't expect that. Perhaps, the disappearance of proximate effect here is just an accidental result. Researchers can do the original experiment again to test this possibility - this is repetition.

If the proximate effect does not disappear, what does that mean? Can we "prove" that the hypothesis is wrong? Still can't. Maybe people do clear the buffer first, but they can retell these words when they do the interference task. In this case, the jamming task does not play a full role.

It can be seen that the hypothetical deductive method is the method commonly used by current psychological researchers. This method uses both induction and deduction. It is a scientific method to evaluate and develop theory by putting forward hypothesis and testing hypothesis.