Introduction to Hypothesis

This presentation discusses the following topics:
Meaning of Hypothesis
Sources of Hypothesis
Variables in hypotheses
Need for Hypothesis
Characteristics of Hypothesis
Functions of Hypothesis
Hypothesis vs. Theory
Variables in Hypothesis
Types of Hypothesis
Developing a Hypothesis
Parameters of Hypothesis
Checklist for Hypothesis
Examples

1. Basics of RESEARCH Dr. C.V. Suresh Babu (Centre for Knowledge Transfer) institute

2. Discussion Topics Meaning of Hypothesis Sources of Hypothesis Variables in hypotheses Need for Hypothesis Characteristics of Hypothesis Functions of Hypothesis Hypothesis vs. Theory Variables in Hypothesis Types of Hypothesis Developing a Hypothesis Parameters of Hypothesis Checklist for Hypothesis Examples

3. Meaning Hypothesis is an assumption that is made on the basis of some evidence A hypothesis is not just a guess — it should be based on existing theories and knowledge. A hypothesis states your predictions about what your research will find. It is a tentative answer to your research question that has not yet been tested. It also has to be testable, which means you can prove or disprove it through scientific research methods (such as experiments, observations and statistical analysis of data).

4. Examples If you get at least 6 hours of sleep, you will do better on tests than if you get less sleep. If you drop a ball, it will fall toward the ground. If you drink coffee before going to bed, then it will take longer to fall asleep . Drinking sugary drinks daily leads to obesity. Smoking cigarettes daily leads to lung cancer. All lilies have the same number of petals is an example of a null hypothesis

5. Sources of Hypothesis Following are the sources of hypothesis: The resemblance between the phenomenon. Observations from past studies, present-day experiences and from the competitors. Scientific theories. General patterns that influence the thinking process of people.

6. Need for Hypothesis A hypothesis is a stepping stone to a soon-to-be proven theory. For a hypothesis to be considered a scientific hypothesis, it must be proven through the scientific method. Like anything else in life, there are many paths to take to get to the same ending.

7. Characteristics Following are the characteristics of hypothesis: The hypothesis should be clear and precise to consider it to be reliable. If the hypothesis is a relational hypothesis, then it should be stating the relationship between variables. The hypothesis must be specific and should have scope for conducting more tests. The way of explanation of the hypothesis must be very simple and it should also be understood that the simplicity of the hypothesis is not related to its significance.

8. Functions of Hypothesis Following are the functions performed by the hypothesis: Hypothesis helps in making an observation and experiments possible. It becomes the start point for the investigation. Hypothesis helps in verifying the observations. It helps in directing the inquiries in the right directions.

9. Hypothesis vs. Theory A theory, in contrast, is a principle that has been formed as an attempt to explain things that have already been substantiated by data. It is used in the names of a number of principles accepted in the scientific community, such as the Big Bang Theory . Because of the rigors of experimentation and control, it is understood to be more likely to be true than a hypothesis is.

10. Variables in hypotheses Hypotheses propose a relationship between two or more variables. An independent variable is something the researcher changes or controls. A dependent variable is something the researcher observes and measures . Example Daily apple consumption leads to fewer doctor’s visits. the independent variable is apple consumption — the assumed cause. The dependent variable is the frequency of doctor’s visits — the assumed effect.

11. Complex hypothesis A complex hypothesis has a relationship between variables. However, it’s a relationship between two or more independent variables and two or more dependent variables.

12. Complex Examples #1 Overweight adults who Value longevity and Seek happiness are more likely than other adults to lose their excess weight and feel a more regular sense of joy

13. Complex Examples #2 Overweight individuals who Eat greasy foods and Eat few vegetables are more likely to have high cholesterol and heart disease.

14. Complex Examples #3 Individuals that smoke cigarettes and live in cities are more likely than others to have respiratory problems and increased cancer.

15. Types The most common forms of hypotheses are: Simple Hypothesis Complex Hypothesis Empirical Hypothesis Null Hypothesis (Denoted by "HO") Alternative Hypothesis (Denoted by "H1") Logical Hypothesis Statistical Hypothesis Associative and Causal Hypothesis Directional Hypothesis Non Directional Hypothesis

16. Null Hypothesis A null hypothesis (H0) exists when a researcher believes there is no relationship between the two variables or a lack of information to state a scientific hypothesis. This is something to attempt to disprove or discredit.

17. Null Hypothesis Examples There is no significant change in my health during the times when I drink green tea only or root beer only. There is no significant change in my work habits when I get 8 and when I get 9 hours of sleep. There is no significant change in the growth of a plant if I use distilled water only or vitamin-rich water.

18. Alternative Hypothesis In an attempt to disprove a null hypothesis, researchers will seek to discover an alternative hypothesis.

19. Alternative Hypothesis Examples My health improves during the times when I drink green tea only, as opposed to root beer only. My work habits improve during the times when I get 8 hours of sleep only, as opposed to 9 hours of sleep only. The growth of the plant improved during the times when I use vitamin-rich water only, as opposed to distilled water only.

20. Logical Hypothesis A logical hypothesis is a proposed explanation possessing limited evidence. Generally, you want to turn a logical hypothesis into an empirical hypothesis, putting your theories or postulations to the test

21. Logical Hypothesis Examples Cacti experience more successful growth rates than tulips on Mars. (Until we're able to test plant growth in Mars' ground for an extended period of time, the evidence for this claim will be limited and the hypothesis will only remain logical.) Beings from Mars would not be able to breathe the air in the atmosphere of the Earth. Creatures found in the bottom of the ocean use aerobic respiration rather than anaerobic respiration.

22. Empirical Hypothesis An empirical hypothesis, or working hypothesis, comes to life when a theory is being put to the test, using observation and experiment. It's no longer just an idea or notion. It's going through some trial and error and perhaps changing around those independent variables.

23. Empirical Hypothesis Examples Roses watered with liquid Vitamin B grow faster than roses watered with liquid Vitamin E. (Here, trial and error is leading to a series of findings.) Women taking vitamin E grow hair faster than those taking vitamin K. Thirsty rats find their way through a maze quicker if there is water at the end of the maze.

24. Statistical Hypothesis A statistical hypothesis is an examination of a portion of a population or statistical model. In this type of analysis, you use statistical information from an area.

25. Statistical Hypothesis Examples For example, if you wanted to conduct a study on the life expectancy of Indians, you would want to examine every single resident of Indian. This is not practical. Therefore, you would conduct your research using a statistical hypothesis or a sample of the Indian population . 30 % of the Indian population lives beyond the age of 70. 2 % of the Indian population get a divorce because of incompatible differences. 45% of the poor in the India are illiterate.

26. Associative and Causal Hypothesis Associative hypothesis occurs when there is a change in one variable resulting in a change in the other variable. Whereas, causal hypothesis proposes a cause and effect interaction between two or more variables.

27. Directional Hypothesis It shows how a researcher is intellectual and committed to a particular outcome. The relationship between the variables can also predict its nature. For example- children aged four years eating proper food over a five-year period are having higher IQ levels than children not having a proper meal. This shows the effect and direction of effect .

28. Directional Hypothesis Example Children aged four years eating proper food over a five-year period are having higher IQ levels than children not having a proper meal. This shows the effect and direction of effect .

29. Non-directional Hypothesis It is used when there is no theory involved. It is a statement that a relationship exists between two variables, without predicting the exact nature (direction) of the relationship.

30. Non-directional Hypothesis Example A researcher might hypothesize that college students will perform differently from elementary school students on a memory task without predicting which group of students will perform better. Also called nondirectional alternative hypothesis ; two-tailed (alternative) hypothesis .

31. Developing a hypothesis 1 . Ask a question Writing a hypothesis begins with a research question that you want to answer. The question should be focused, specific, and researchable within the constraints of your project. Do students who attend more lectures get better exam results ?

32. Developing a hypothesis 2 . Do some preliminary research Your initial answer to the question should be based on what is already known about the topic. Look for theories and previous studies to help you form educated assumptions about what your research will find. At this stage, you might construct a conceptual framework to identify which variables you will study and what you think the relationships are between them .

33. Developing a hypothesis 3. Formulate your hypothesis Now you should have some idea of what you expect to find. Write your initial answer to the question in a clear, concise sentence. Attending more lectures leads to better exam results.

34. Developing a hypothesis 4. Refine your hypothesis You need to make sure your hypothesis is specific and testable. There are various ways of phrasing a hypothesis, but all the terms you use should have clear definitions, and the hypothesis should contain: The relevant variables The specific group being studied The predicted outcome of the experiment or analysis

35. Developing a hypothesis 5. Phrase your hypothesis in three ways To identify the variables, you can write a simple prediction in  if…then form. The first part of the sentence states the independent variable and the second part states the dependent variable. If a first-year student starts attending more lectures, then their exam scores will improve. In academic research, hypotheses are more commonly phrased in terms of correlations or effects, where you directly state the predicted relationship between variables. The number of lectures attended by first-year students has a positive effect on their exam scores. If you are comparing two groups, the hypothesis can state what difference you expect to find between them. First-year students who attended most lectures will have better exam scores than those who attended few lectures.

36. Developing a hypothesis 6. Write a null hypothesis If your research involves statistical hypothesis testing, you will also have to write a null hypothesis. The null hypothesis is the default position that there is no association between the variables. The null hypothesis is written as H , while the alternative hypothesis is H 1 or H a . H : The number of lectures attended by first-year students has no effect on their final exam scores. H 1 : The number of lectures attended by first-year students has a positive effect on their final exam scores.

37. Hypothesis Checklist Here are some important questions to ask: Is the language clear and focused? Does the hypothesis introduce the research topic? Does the hypothesis include both an independent and dependent variable? Are they easy to identify? Can the hypothesis be tested through experimentation? Does the hypothesis explain what you expect to happen during your experiment?

38. Parameters of a Good Hypothesis Step 1: Ask Yourself Questions Define the independent and dependent variables very specifically, and don't take on more than you can handle. Keep yourself laser-focused on one specific cause-and-effect theory .

39. Parameters of a Good Hypothesis Step 2: Be Logical and Use Precise Language Keep your language clean and simple. State your hypothesis as concisely, and to the point, as possible. A hypothesis is usually written in a form where it proposes that, if something is done, then something else will occur. Usually , you don't want to state a hypothesis as a question. You believe in something, and you're seeking to prove it. For example: If I raise the temperature of a cup of water, then the amount of sugar that can be dissolved in it will be increased.

40. Parameters of a Good Hypothesis Step 3: Make Sure Your Hypothesis Is Testable Any hypothesis will need proof. Your audience will have to see evidence and reason to believe your statement. For example, I may want to drink root beer all day, not green tea. If you're going to make me change my ways, I need some sound reasoning and experimental proof — perhaps case studies of others who lost weight, cleared up their skin and had a marked improvement in their immunity by drinking green tea.

41. Research question Hypothesis Null hypothesis What are the health benefits of eating an apple a day? Increasing apple consumption in over-60s will result in decreasing frequency of doctor’s visits. Increasing apple consumption in over-60s will have no effect on frequency of doctor’s visits. Which airlines have the most delays? Low-cost airlines are more likely to have delays than premium airlines. Low-cost and premium airlines are equally likely to have delays. Can flexible work arrangements improve job satisfaction? Employees who have flexible working hours will report greater job satisfaction than employees who work fixed hours. There is no relationship between working hour flexibility and job satisfaction. How effective is high school sex education at reducing teen pregnancies? Teenagers who received sex education lessons throughout high school will have lower rates of unplanned pregnancy than teenagers who did not receive any sex education. High school sex education has no effect on teen pregnancy rates. What effect does daily use of social media have on the attention span of under-16s? There is a negative correlation between time spent on social media and attention span in under-16s. There is no relationship between social media use and attention span in under-16s.