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Research Design in Occupational Education
Copyright 1997. James P. Key. Oklahoma State University
Except for those materials which are supplied by different departments of the University
(ex. IRB, Thesis Handbook) and references used by permission.





Sources of Reliable Knowledge

Reliable knowledge comes from many different sources. Even toward the end of the twentieth century, it is still hard to imagine that scientific methods can provide answers to questions that have interested man for the preceding two thousand years. However, the prevailing attitude remains that problems can be resolved through information from the following sources:

Common Sense

Although these are reliable sources of knowledge in many respects, all still have limitations to their reliability when used as a basis for research. For instance, each person has their own experience base upon which to make decisions. However, this experience base is a sample of one when compared to the experience which could be used as the base if it were not limited to an individual. Even if we have multiple experiences from many individuals, we have to interpret them in the context of those person’s backgrounds and situations if they are to provide reliable knowledge for research or decision making.


Everyone is familiar with experience as a source of reliable knowledge. They have all used it to solve problems in life. The extent which they can learn from other people’s experiences seems to be directly related to intelligence. This use of experience has generally been the source of much of the wisdom accumulated by the human race. Much of the progress of mankind has been based on experience.

Although experience is a much used and reliable source of knowledge, it is not without its limitations. The same situation may result in entirely different experiences for two different people. For instance, the ocean may be a delightful place for one person who enjoys swimming and surfing. It may be a terrifying threat to one who does not know how to swim. Experience depends on the background of the individual as well as the context in which it occurs. For example, a child may have learned that a large piece of candy is preferable over a small piece. When given the choice of coins, he may incorrectly choose a nickel over a dime based on his past experience with the candy. A researcher must be very cautious when using experience in the search for reliable knowledge.


Reason is a source of knowledge based on logic. Logic is primarily made up of inductive and deductive thinking. Reason takes the quantitative and proof approach to reliable knowledge rather than the more subjective qualitative approach of experience. For instance, perfect inductive thinking uses the power of observation to record all possible occurrences as a foundation for extremely reliable knowledge. If one observed all the crows on a ranch in Oklahoma, they could be very sure that all crows there were black. Likewise, deductive thinking could lead that individual to develop a deductive syllogism: Since all crows are black (major premise), and this bird is a crow (minor premise), therefore, it must follow that this bird is black (conclusion). Such proofs do not depend upon situation or interpretation; they speak for themselves as bases of reliable knowledge.

A researcher must be cautious, even when using reason as a basis for reliable knowledge. In the case of the crows observed on the ranch in Oklahoma, perhaps it could be said with certainty that all the crows on that ranch were black. However, would that hold true for the entire county? state? country? world? What might be perfect induction for the ranch, where every crow was observed, becomes quite a different matter when the area is enlarged. Now perfect induction may become impractical or impossible, and our observations on the ranch may be only a small sample of convenience. It no longer has the reliability or representativeness it needs to be depended on as a basis of sound knowledge.

Likewise, our deductive thinking has limitations. Deductive logic has certain rules which must be followed in order for the conclusion to be true. First, the major and minor premises must both be true for the conclusion to follow. Also, the syllogism must be correctly constructed and follow a logical order. In addition, word usage must be considered to avoid different meanings. In our example, the major premise is that all crows are black. In order for the conclusion to be necessarily true, the premises must be absolutely true. For instance, an albino crow would negate the reliability of our deductive thinking, because it is an exception to the major premise. Consider the following syllogism.

All crows are black (major premise).

This bird is black (minor premise).

Therefore, this bird is a crow (conclusion).

It might appear to be very logical, but most people would say quickly, "That is not necessarily true! It might just be a black bird." They could be absolutely correct, too. What is wrong with the syllogism? It is incorrectly constructed. Look at the first syllogism about the crows.

Major premise All crows are black. If all M are P, and

Minor premise This bird is a crow. this S is M,

Conclusion        This bird is black.        this S is P.

It must follow the M-P, S-M, S-P sequence in order to be correct. Therefore keep in mind that even reasoning has its limitations.


How does a person become an authority? Generally, authority is bestowed upon a person by other people. If people recognize a person as an authority, this bestows the authoritative prestige and power which goes along with it. Such recognition of people like Einstein or Schweitzer may have been justified, including their use as reliable sources of knowledge. But there are probably as many cases where this recognition was unjustified as it was justified. For instance the recognition of Hitler as an authority could be called "blind" recognition. The appeal of authority as a source of knowledge is not unreasonable. With the explosion of information, no one can be knowledgeable in very many areas. Therefore they have to depend on others who are more knowledgeable in those areas. This gives rise to authorities. Care must be exercised in depending upon this source.

Mander (1947), in Logic for the Millions, indicated there were four criteria which could be used for evaluating a person as an authority. First, the expert must be identified. Scientific reports and dissertations are required to cite their sources so they may be identified and evaluated. Likewise, authorities need to be identified so they can be evaluated on an individual basis. Second, the authority should be recognized as such by the members of profession in which he claims competency. The authority's reputation among his colleagues can be a rough estimate of the reliability of his authority. True, some prejudiced members might discredit a true authority, but the failure to use this criterion would deny the persons most capable of judging the knowledge the right to do so. Third, the cited authority should be living. Although the person might have been an authority in their time, they might have even changed their minds in changing times. Fourth, the authority should not be biased. Prejudices, biases and stereotypes would interfere with any clear rational judgment. True, it is difficult to evaluate an authority's biases, but this should not keep us from trying to make these judgments if it is possible to do so.

Revelation and Intuition

Revelation is generally considered to be a direct and immediate insight into "truth" or "reality" from a source greater than ourselves, often presumed to be from God. If these insights are considered to have a natural source, such as self, they are considered to be intuitions.

Most of us have experienced the feeling that we should make a certain decision simply because it feels like we should. Maybe we feel we should trust that person or choose that answer on the test. Maybe later it turned out that it was good we trusted that person as we became good friends. Maybe that answer on the test was correct. The only way of evaluating intuitions is by empirically verifying their consequences. The reliability of this source of knowledge cannot usually be determined until much later.

Similarly, revelations can only be verified by empirical experience. This makes verification of revelations even more difficult than intuitions since their source is presumed to be outside of man’s experience from a supernatural source. For example, proclamations that the world will end on a certain day are invalid when that day passes. Many times revelations are very personal in nature. Their verification can only be done through the experience of that individual. There are no rigorous criteria which can be placed by which to judge a revelation. A revelation may have tremendous importance for a person experiencing it, they may have trouble convincing others of its validity or reliability.

Common Sense

Common sense is a very popular source of reliable knowledge among many people. It appeals to many who scoff at "ivory tower theories". It is used many times to justify preconceived beliefs or to support generally accepted truths. Common sense supported the belief that the world was flat in Columbus day. Fear and superstition supported this belief. It was not until Columbus disproved the belief by sailing to America that this belief was exposed as false. It is considered "common sense" by many in education that students learn best when the classroom is very orderly and quiet. Some research has challenged this belief by showing that tremendous learning can take place in classrooms where it may appear there is chaos because of the noise and activity. However, if the students are actively involved and seeking answers to problems individually and in groups, much greater learning may be taking place than in the sterile, quiet, orderly classroom. However, care must be taken when using common sense as a reliable source of knowledge.

If all this is true, then what can be trusted as a reliable source of knowledge? The answer is not simple. True, all these sources have their limitations. But on the other hand, all also have a certain amount of reliability for producing "truth." Combinations of sources are better than single sources alone in most cases. A systematic approach to their use also adds to their credibility. This leads to the scientific approach to problem solving.

The Scientific Method

Charles Darwin is generally credited with introducing the scientific method in the pursuit of knowledge. His book, The Life and Letters of Charles Darwin (1989), described how he arrived at the new approach. It was generally a process of moving inductively from the gathering of observations to the development of hypotheses based on those observations. Next, it involved deductively reasoning the consequences that would follow if a hypothesis were true. Data would then be gathered relevant to the consequences through observation, testing, and experimentation. Finally, the hypothesis would be confirmed or rejected based upon the data gathered. The exact wording of the steps of the scientific method will vary from author to author, but their sequence and systematic approach have remained constant over time.

Steps of the Scientific Method

1. Definition of the Problem

Most scientific inquiry evolves from a problem or question to be answered. Bacon and Darwin generally moved inductively from their observations to the defining of the problem. Perfect induction involves observing every possible instance of a phenomenon. With a population of any size, this is usually impractical or impossible. Therefore, imperfect induction developed through sampling. In order to have reliable knowledge based upon a sample, one must have a representative sample. That is, instances observed in the small group (sample) must truly represent the characteristics of the large group (population). There are various sampling methods employed to try to arrive at this "best" representative sample, ranging from random to stratified, proportional, cluster, systematic, or purposive. Each are designed to get the highest probability of representativeness of the sample possible under the given circumstances and situation. The homogeneity or heterogeneity of the characteristic of the population under observation greatly determines the probability of representativeness and the success of the sampling methods. It also greatly determines the size of the sample needed to be most representative. For example, getting a representative sample of a barrel of gasoline would be much easier than getting a representative sample of a group of steaks. Imperfect induction introduces new knowledge, but it can only arrive at conclusions with varying degrees of probability.

2. Statement of Hypothesis

The hypothesis is the "educated guess" which provides a tentative explanation of the problem. It is derived from the problem and provides a tentative explanation for the problem. An extensive review of the literature greatly enhances the "education" of the hypothesis.

3. Deductive Reasoning

Through deduction, the investigator analyzes the implications of the hypothesis. That is, he considers what would be observed if the hypothesis were true. Deductive arguments are stated as syllogisms. The categorical syllogism organizes thinking by categories. The illustration of the crows given earlier was a categorical syllogism. Another type is the hypothetical, or an "if-then" statement. If I pass this test, I will pass the course. I passed the test. Therefore, I passed the course. The alternative syllogism is an "either-or" statement. Either I will earn some money or I will go hungry. I did not earn any money. Therefore, I will go hungry. The disjunctive syllogism is a "can’t be both" statement. It cannot be both a rainy day and a good day to make hay. It is a rainy day. Therefore, it is not a good day to make hay. Deductive arguments are limited to knowledge that is already known. However, if the major premise and the minor premise are both true and the structure of the argument is correct, then the conclusion must necessarily follow and be true.

4. Collection and Analysis of Data

The deduced implications of the hypothesis are tested by gathering data through observation, testing, and experimentation that is relevant to the hypothesis.

5. Confirming or Rejecting the Hypothesis

The data is collected and analyzed so the results can be used to confirm or reject the hypothesis. The investigator determines if the findings support or do not support the hypothesis. He does not claim to prove a hypothesis, since the scientific method, although very systematic and thorough, cannot claim absolute truth.

The steps of the scientific method are conceptually separate, but it is well to remember there are no absolute boundaries, and they tend to overlap in practice. Sometimes the sequence even varies from the prescribed order.



1. Name six sources from which you can obtain dependable knowledge about education.

2. Define in a short statement or paragraph each of the six sources of dependable knowledge about education.

3. Demonstrate your understanding of the deductive syllogism by writing an example not used in the information sheet.

4. Demonstrate your understanding of inductive reasoning by writing an example not used in the information sheets.

5. Discuss how deductive and inductive reasoning may be used in the scientific method of obtaining dependable knowledge about education.

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