HypothesisWhat a hypothesis is?
The hypothesis is a supposition or proposed explanation made based on limited evidence as a starting point for further investigation. A research hypothesis (H1) is the statement created by researchers when they speculate upon the outcome of a research or experiment. In research, there is a convention that the hypothesis is written in two forms, the null hypothesis, and the alternative hypothesis (called the experimental hypothesis when the method of investigation is an experiment)
1. A supposition or explanation (theory) that is provisionally accepted to interpret certain events or phenomena, and to provide guidance for further investigation. A hypothesis may be proven correct or wrong and must be capable of refutation. If it remains unrefuted by facts, it is said to be verified or corroborated.
2. Statistics: An assumption about certain characteristics of a population. If it specifies values for every parameter of a population, it is called a simple hypothesis; if not, a composite hypothesis. If it attempts to nullify the difference between two sample means (by suggesting that the difference is of no statistical significance), it is called a null hypothesis.
The hypothesis is generated via several means but is usually the result of a process of inductive reasoning where observations lead to the formation of a theory. Scientists then use a large battery of deductive methods to arrive at a hypothesis that is testable, falsifiable and realistic. Every true experimental design must have this statement at the core of its structure, as the ultimate aim of any experiment.
Our hypothesis should:
- Be written in clear, concise language
- Have both an independent and dependent variable
- Be falsifiable – is it possible to prove or disprove the statement?
- Make a prediction or speculate on an outcome
- Be practicable – can you measure the variables in question?
Hypothesize about a proposed relationship between two variables, or intervention into this relationship hypothesis.
Hypotheses, in a scientific context, is a testable statement about the relationship between two or more variables or a proposed explanation for some observed phenomenon. In a scientific experiment or study, the hypothesis is a brief summation of the researcher's prediction of the study's findings, which may be supported or not by the outcome. Hypothesis testing is the core of the scientific method.
The researcher's prediction is usually referred to as an alternative hypothesis, and any other outcome as the null hypothesis basically, the opposite outcome to what is predicted. (However, the terms are reversed if the researchers are predicting no difference or change, hypothesizing, for example, that the incidence of one variable will not increase or decrease in tandem with the other.) The null hypothesis satisfies the requirement for falsifiability: the capacity for a proposition to be proven false, which some schools of thought consider essential to the scientific method. According to others, however, testability is adequate, because if there is sufficient support for a hypothesis it is not necessary to be able to conceive of a contrary outcome.
The null hypothesis is, therefore, the opposite of the alternative hypothesis in that it states that there will be no change in behaviour. At this point, you might be asking why we seem so interested in the null hypothesis. Surely the alternative (or experimental) hypothesis is more important? Well, yes it is. However, we can never 100% prove the alternative hypothesis. What we do instead is see if we can disprove, or reject, the null hypothesis. If we reject the null hypothesis, this doesn’t really mean that our alternative hypothesis is correct – but it does provide support for the alternative / experimental hypothesis.