Variables Definition of variable: is a characteristic or

attribute of a person or object (polit, 2004).

Example of some variables• Weight.• Body temperature.• Blood pressure reading.• Stress level.• Anxiety level

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Types of variables

1- Continuous variables: variable can take on a range of different values. Their values can be presented on continuum.

Examples . Age . weight, . height.

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2- Categorical variables: variables that take on a much smaller range of values.

Example: . Male or female. Pregnant / not pregnant .. Smoker / non-smoker.. HIV positive/ HIV negative.

. When the categorical variables take on only two values, they are sometimes referred to as dichotomous variables.

Some additional examples of categorical variables.. marital state (married, single, divorce, and widowed).

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3. Dependent variables: the outcome variable of interest (effect). The dependent variable usually is the variable the researcher is interested in understanding, explaining or predicting.

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4- Independent variable: the variable that is believed to cause or influence the dependent variable. In the experimental research the independent variable is the variable that is manipulated.

Note: the presumed cause is referred to as the independent

Example: the extent to which lung cancer (dependent variable) Depends on smoking behavior (independent variable).

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5. Extraneous variable: variable that confounds the

relationship between independent variable and dependent variable that needs to be controlled either

in the research design or through statistical

procedure.

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6. Homogenous variable: the degree to which objects or variables are similar characteristic.

7- Heterogeneous variable: the degree to which objects or variables are dissimilar characteristic

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Example of independent (IDV) and dependent variables (DV)

1- Do physician administer greater amount of narcotic drug to men than women.

DV IDV Amount of narcotic Gender

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2- what is the effect of activity and bed rest on weight reduction among Gestational diabetes women.

DV IDV Weight reduction Activity& rest

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3- Is adherence to therapeutic regime decrease the incidence of PIH.

DV IDV Incidence of PIH Adherence of therapeutic regime

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Hypotheses

Definition of hypothesis : It is a statement of predicted relationship between two or more than two variables.

Note: The difference between problem statement and hypothesis is that Hypothesis translate problem statements into predictions of expected outcomes.

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Types of Hypotheses

1. Simple Hypothesis : A hypothesis that predicts the relationship between one dependent variable (DV) and one independent variable (IDV). It is easy to test and analyze it.

Example There is a relationship between smoking and

development of stroke among hypertensive patients in Gaza strip.

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2. Complex hypothesis: (Multivariate hypothesis) : A hypothesis that predicts the relationship between

two or more dependent variables and two or more independent variables.

Example: There is a relationship between high fat diet and

smoking and development of atherosclerosis and stroke among hypertensive patients in Gaza strip.

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3. Directional hypothesis: is one that specifies the expected direction of the relationship between variables. The researcher predicts not only the existence of a relationship but also the nature of the relationship.

The key word of directional hypothesis is (less, more, greater, lower, higher, positive, negative)

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Example

1. Hypertensive smoker's patients are more likely to develop stroke than hypertensive non-smoker's patients.

2. Older midwives are less likely to express approval of the expanding roles than

younger midwives.

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4. Statistical hypothesis (Null hypothesis): is one that stated there is no relationship between variables.

Example1. Hypertensive smoker's patients are likely to develop stroke as hypertensive non-smoker's patients.

2. Older midwives are likely to express approval of the expanding roles as younger physiotherapist.

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Hypothesis criteria

The hypothesis should includes

1. Population2. Variables3. Reflect the problem statement

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Exercise

Look at the following hypotheses, and write down what are the two variables, statement of purpose, and null hypothesis.

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1. Men and women with arthritis differ in their responsiveness to heat treatment.

(Hypothesis)

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Independent variable: sex (male or female)

Dependent variable: responsiveness to

heat treatment

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• Problem statement

a. Statement of purpose: The purpose of this study is to explain the relationship between men and women and their responsiveness to heat treatment among patients with arthritis.

b. Research question: what is the relationship between men and women and their responsiveness to heat treatment among patients with arthritis.

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2. There is a difference in professional competence between midwives who trained in hospital-based training schools than those who trained in polytechnic-based training schools

(Hypothesis)

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Independent variable: Type of training establishment

(hospital-based or polytechnic-based)

Dependent variable: professional competence

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• Problem statement

a. Statement of purpose: The purpose of this study is to compare between Type of training establishment (hospital-based or polytechnic-based) and professional competence among midwives.

b. Research question: Are there a relationship between Type of training establishment (hospital-based or polytechnic-based) and professional competence among midwives.

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Statistical hypothesis (Null hypothesis)

There is no relationship between Type of training

establishment (hospital-based or polytechnic-based)

and professional competence among midwives.

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