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RESEARCH HYPOTHESIS

Characteristics of Testable Hypotheses

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it tackles about the hypothesis of research such as the different types of hypothesis and many more

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Page 1: Characteristics of Testable Hypotheses

RESEARCH HYPOTHESIS

Page 2: Characteristics of Testable Hypotheses

Hypothesis

-is a prediction, almost always involving the predicted relationship between two or more variable.

-State researchers’ expectations about relationships among study variables.

Hypotheses are predictions of expected outcomes; The research question identifies the concepts under

investigation and asks how the concepts might be related;

A hypothesis is the predicted answer. Most quantitative studies are designed to test

hypotheses through statistical analysis.

Page 3: Characteristics of Testable Hypotheses

Characteristics of Testable Hypotheses

Testable research hypotheses state the expected relationship between the independent variable (the presumed cause or antecedent) and the dependent variable (the presumed effect or outcome) within a population.

Page 4: Characteristics of Testable Hypotheses

Example of a research hypothesis:

Gungor and Beji (2007) tested the effect of fathers’ attendance during labor and delivery on the childbirth experience in Turkey, where the prevailing culture has not supported a role for fathers during the birth process.

They hypothesized that women whose partners attended labor and delivery would need less pain-relieving medication than women who were alone.

Page 5: Characteristics of Testable Hypotheses

The population is women giving birth in Turkish hospitals;

the independent variable is partners’ presence or absence during labor and delivery;

the dependent variable is the mothers’ need for pain medication.

Page 6: Characteristics of Testable Hypotheses

Researchers occasionally present hypotheses that do not make a relational statement, as in the following example:

Pregnant women who receive prenatal

instruction by a nurse regarding postpartum experiences are not likely to experience postpartum depression.

This statement expresses no anticipated relationship;

in fact, there is only one variable (postpartum depression), and a relationship by definition requires at least two variables.

Page 7: Characteristics of Testable Hypotheses

Without a prediction about an anticipated relationship, the hypothesis cannot be tested using standard statistical procedures.

In our example, how would we know whether the hypothesis was supported—what standard would we use to decide whether to accept or reject the hypothesis?

To illustrate the problem more concretely, suppose we asked a group of new mothers who had been given prenatal instruction the following question:

“On the whole, how depressed have you been

since you gave birth? Would you say

(1) extremely depressed, (2) moderately

depressed, (3) a little depressed, or (4) not at all depressed?”

Page 8: Characteristics of Testable Hypotheses

Based on responses to this question, how could we compare the actual outcome with the predicted outcome? Would all the women have to say they were “not at all depressed?”

Would the prediction be supported if 51% of the women said they were

“not at all depressed” or “a little depressed?”

It is difficult to test the accuracy of the prediction.

Page 9: Characteristics of Testable Hypotheses

A test is simple, however, if we modify the prediction as follows:

Pregnant women who receive prenatal instruction are less likely than those who do not to experience postpartum depression.

Here, the dependent variable is the women’s depression, and the independent variable is their receipt versus nonreceipt of prenatal instruction.

The relational aspect of the prediction is embodied in the phrase less...than.

If a hypothesis lacks a phrase such as more than, less than, greater than, different from, related to, associated with, or something similar, it is not readily testable.

Page 10: Characteristics of Testable Hypotheses

To test the revised hypothesis, we could ask two groups of women with different prenatal instruction experiences to respond to the question on depression and then compare the groups’ responses.

The absolute degree of depression of either group would not be at issue.

Hypotheses should be based on justifiable rationales.

Hypotheses often follow from previous research findings or are deduced from a theory.

Page 11: Characteristics of Testable Hypotheses

Wording of Hypotheses There are many ways to word

hypotheses, but they should be worded in the present tense.

A hypothesis can predict the relationship between a single independent variable and a single dependent variable (a simple hypothesis) or

it can predict a relationship between two or more independent variables or two or more dependent variables (a complex hypothesis).

Page 12: Characteristics of Testable Hypotheses

Example of a complex hypothesis—multiple independent variables:

Schweitzer and colleagues (2007) hypothesized that, among patients with heart failure, depression

(IV1), anxiety (IV2), and self-efficacy (IV3) are independent predictors of adherence to medical treatment

recommendations (DV).

Page 13: Characteristics of Testable Hypotheses

A number of studies have found, for example, that cigarette smoking (the IV), can lead to both lung cancer (DV1) and coronary disorders (DV2).

Complex hypotheses are common in studies that try to assess the impact of a nursing intervention on multiple outcomes.

Page 14: Characteristics of Testable Hypotheses

Example of a complex hypothesis—multiple dependent variables: McLeod and colleagues (2007)

hypothesized that people with auditory hallucinations

who participated in a cognitive behavioral intervention (IV) would, compared with nonparticipants, experience fewer hallucinations

(DV1), lower anxiety (DV2), and fewer symptoms of distress (DV3).

Page 15: Characteristics of Testable Hypotheses

Hypotheses can be stated in various ways, as in the following example: 1. Older patients are more at risk of experiencing a fall than

younger patients.

2. There is a relationship between a patient’s age and the risk of falling.

3. The older the patient, the greater the risk that she or he will fall.

4. Older patients differ from younger ones with respect to their risk of falling.

5. Younger patients tend to be less at risk of a fall than older patients.

6. The risk of falling increases with the age of the patient.

Page 16: Characteristics of Testable Hypotheses

In all of these examples, the hypotheses indicate the population (patients), the

independent variable (patients’ age), the dependent variables (risk of falling), and

an anticipated relationship between them.

Page 17: Characteristics of Testable Hypotheses

Hypotheses can be either directional or nondirectional.

Directional hypothesis is one that specifies not only the

existence but the expected direction of the relationship between variables. In the six versions of the hypothesis above, versions 1, 3, 5, and 6 are directional because there is an explicit prediction that older patients are at greater risk of falling than younger ones.

Mas specific

Page 18: Characteristics of Testable Hypotheses

Nondirectional hypothesis

does not stipulate the direction of the relationship, as illustrated in versions 2 and 4.

These hypotheses state the prediction that a patient’s age and the risk of falling are related, but they do not specify whether the researcher thinks that older patients or younger ones are at greater risk.

Page 19: Characteristics of Testable Hypotheses

Hypotheses based on theory are almost always directional because theories explain phenomena and provide a rationale for explicit expectations.

Existing studies also offer a basis for directional hypotheses.

When no theory or related research exists, or when the findings of related studies are contradictory, non directional hypotheses may be appropriate.

Page 20: Characteristics of Testable Hypotheses

Another distinction is the difference between research and null hypotheses.

Research hypotheses (also referred to as substantive

or scientific hypotheses) are statements of expected relationships between variables.

All the hypotheses presented thus far are research hypotheses that indicate actual expectations.

Page 21: Characteristics of Testable Hypotheses

Null hypotheses (or statistical hypotheses) state that no

relationship exists between the independent and dependent variables.

The null form of the hypothesis used in our preceding example would be:

“Older patients are just as likely as younger patients to fall.”

Research reports typically present research rather than null hypotheses.

Page 22: Characteristics of Testable Hypotheses

Hypothesis Testing and Proof Hypotheses are formally tested through statistical analysis. Researchers seek to determine through statistics whether

their hypotheses have a high probability of being correct. Statistical analysis does not provide proof, it only supports

inferences that a hypothesis is probably correct (or not). Hypotheses are never proved;rather, they are accepted or

supported. Findings are always tentative. Certainly, if the same results are replicated in numerous

investigations, then greater confidence can be placed in the conclusions.

Hypotheses come to be increasingly supported with mounting evidence.

Page 23: Characteristics of Testable Hypotheses

To illustrate why this is so, suppose we hypothesized that height and weight are related.

We predict that, on average, tall people weigh more than short people.

We then obtain height and weight measurements from a sample and analyze the data.

Now suppose we happened by chance to get a sample that consisted of short, heavy people, and tall, thin people.

Our results might indicate that no relationship exists between a person’s height and weight.

Would we then be justified in stating that this study proved or demonstrated that height and weight are unrelated?

Page 24: Characteristics of Testable Hypotheses

CRITIQUING RESEARCH PROBLEMS, RESEARCH QUESTIONS, AND HYPOTHESES In critiquing research reports, you will need to

evaluate whether researchers have adequately communicated their research problem.

The delineation of the problem, statement of purpose, research questions, and hypotheses set the stage for the description of what was done and what was learned.

Ideally, you should not have to dig too deeply to decipher the research problem or to discover the questions.

Page 25: Characteristics of Testable Hypotheses

A critique of the research problem involves multiple dimensions.

Substantively,you need to consider whether the problem has significance for nursing and has the potential to produce evidence to improve nursing practice.

Studies that build on existing knowledge in a meaningful way are well-poised to make contributions to evidence-based nursing practice.

Researchers who develop a systematic program of research, building on their own earlier findings, are especially likely to make significant contributions.

Page 26: Characteristics of Testable Hypotheses

Another dimension in critiquing the research problem concerns methodologic issues—in particular, whether the research problem is compatible with the chosen research paradigm and its associated methods.

You should also evaluate whether the statement of purpose or research questions have been properly worded and lend themselves to empirical inquiry.

Page 27: Characteristics of Testable Hypotheses

If there are hypotheses, you should evaluate whether the hypotheses are logically connected to the research problem and whether they are consistent with available knowledge or relevant theory.

The hypothesis is a valid guidepost to scientific inquiry only if it is testable.

To be testable, the hypothesis must contain a prediction about the relationship between two or more measurable variables.

Page 28: Characteristics of Testable Hypotheses

Specific guidelines for critiquing research problems, research questions, and hypotheses are presented in

Box 6.3.

Page 29: Characteristics of Testable Hypotheses

GUIDELINES FOR CRITIQUING RESEARCH PROBLEMS, RESEARCHQUESTIONS, AND HYPOTHESES

Page 30: Characteristics of Testable Hypotheses

1. What is the research problem? Is the problem statement easy to locate and clearly stated? Does

the problem statement build a cogent and persuasive argument for the new study?

2. Does the problem have significance for nursing? How might the research contribute to nursing

practice, administration, education, or policy?

3. Is there a good fit between the research problem and the paradigm within which the research

was conducted? Is there a good fit with the qualitative research tradition (if applicable)?

4. Does the report formally present a statement of purpose, research question, and/or hypotheses?

Is this information communicated clearly and concisely, and is it placed in a logical and useful

location?

5. Are purpose statements or questions worded appropriately? (e.g., are key concepts/variables

identified and the population of interest specified? Are verbs used appropriately to suggest the

nature of the inquiry and/or the research tradition?)

6. If there are no formal hypotheses, is their absence justified? Are statistical tests used in analyzing

the data despite the absence of stated hypotheses?

7. Do hypotheses (if any) flow from a theory or previous research? Is there a justifiable basis for the

predictions?

8. Are hypotheses (if any) properly worded—do they state a predicted relationship between two or

more variables? Are they directional or nondirectional, and is there a rationale for how they

were stated? Are they presented as research or as null hypotheses?