Research Variables

Variable

Variable

- a characteristic that can be manipulated or observed and that can take on different values, either quantitively or qualitatively

- e.g. height, weight, and amount of forward reach

Independent Variable

- a predictor variable

- it is a condition, intervention, or characteristics that will be predict or cause a given outcome

- can be an active variable or attribute variable

Active Variable

is one that is manipulated by the experimenter so that subjects are assigned to different groups.

Therapy or Treatment

- identify the active variable:

• subjects are assigned to receive therapy or a placebo

Attribute Variable

- are inherent characteristics of the samples

- cannot be manipulated and when the effect of one or more variable is studied, the research cannot be considered as a true experiment

- e.g. age, grouping subjects according to age, facial features

Stroke

- identify the attribute variable:

• effects of stretching maneuver to patients with stroke

True Experiment

focused on the active variable.

Blocking Variable

- when grouping is made on the basis of an attribute, and not through random assignment

- grouping is made if the attribute variable can be an extraneous variable or it will have an effect on the independent variable

Amount of postural sway

- identify the blocking variable:

• age with amount of postural sway

• Control

• Manipulation

• Randomization

3 determinants of experimental research.

Dependent Variable

- outcome variable

- response or effect that is presumed to vary depending on the independent variable

Low back pain intensity

- identify the dependent variable:

• comparison of the effect of manual therapy and manual therapy combined with exercise is decreasing low back pain intensity

Extraneous Variable

- nuisance or intervening variable

- is any factor that is not directly related to the purpose of the study, but may affect the dependent variable

- can be extrinsic or intrinsic

Extrinsic Factors

- emerge from environment and experimental situation

- e.g. environment and temperature

Intrinsic Factors

- represent personal characteristics of the subjects of the study

- e.g. patient’s emotional status and mental capacity

• Independent: OSCE

• Dependent: Clinical competency

• Extrinsic: Location, stations, curtains

• Intrinsic: Duty hours will affect their study hours

- identify the variables:

• Study: Effect of the academic program in PLM in enhancing the clinical competency of the interns

• Methodology: The subject interns will undergo an Objective Structured Clinical Examination (OSCE) to measure their clinical competency before and after the program. The location of the study is in Gusaling Villegas. The stations will be divided by curtains. The rater will be trained an hour before the day of the examination.

Confounding Variable

a variable unrelated to the study, but can influence independent variable directly (the effect is more on the independent variable.

• Independent: OSCE

• Confounding Variable: Rater/Trainer

- identify the independent and confounding variable:

• Study: Effect of the academic program in PLM in enhancing the clinical competency of the interns

• Methodology: The subject interns will undergo an Objective Structured Clinical Examination (OSCE) to measure their clinical competency before and after the program. The location of the study is in Gusaling Villegas. The stations will be divided by curtains. The rater will be trained an hour before the day of the examination.

Qualitative Variable (Nominal Variable)

- is one whose categories are simply used as labels to distinguish one group from another, rather than as basis for saying that one group is greater or less

- labeling; no hierarchy or levels

- e.g. sex, urban-rural classification, religion

Dichotomous Variable

- these are variable that can only take two values; two choices

- e.g. passed or fail, male or female, yes or no

Quantitative Variable

- is one whose categories can be measured and ordered according to quantity or amount

- values can be expressed numerically

- e.g. ROM, head circumferences of a baby

Discrete Variables

- if it can only assume integral values or whole numbers; countable

- e.g. number of persons, beats per minute

Continuous Variable

- it takes on every value along a continuum within a defined range between two values and an indefinitely large amount or fractions of values like decimals

- can never be measured exactly but they are limited by precision of the measuring instrument

- e.g. range of motion measured by goniometer

Nominal

- classificatory scale where the categories are used as labels only (does not represent quantity)

- e.g. male/female, gender, race, blood groups

Ordinal

- same characteristics as the nominal scale with additional feature: categories can be ordered or ranked but does not have equal values in between ranks

- e.g. score in MMT, likert scale

Categorical Variables

variables that falls under nominal and ordinal scale.

Interval

- same characteristics as the ordinal scale with additional features: distances between all adjacent classes are equal; zero point is arbitrary and does not mean absence of the characteristics

- e.g. temperature in Celsius

Ratio

- same characteristics as interval with additional features: a meaningful zero point exist

- e.g. weight, height, blood pressure, TUG test