US Preventative Services Task Force - develop evidence-based guidelines for
healthcare
Cochrane Collaboration - develop and disseminate systemic reviews of healthcare
interventions
Florence Nightingale David - produced the first edition of Tables of the Correlation
Coefficient
population - The entire group having some characteristic (eg, all people with
depression, all residents of the United States). Often a sample is taken of the population
and then the results are generalized to that population.
sample - A group selected from the population in the hope that the smaller group will be
representative of the entire population.
parameter - characteristic of a population
statistic - characteristic of a sample
descriptive statistic - numerical or graphical summaries of data, and may include charts,
graphs, and simple summary statistics such as means and standard deviations to
describe characteristics of a population sample
inferential statistics - statistical techniques (e.g., chi-square test, the t test, the one-way
ANOVA) that allow conclusions to be drawn about the relationships found among
different variables in a population sample
quantitative variables - a characteristic that can be measured numerically, a
characteristic with numeric values that have meaning and for which arithmetic
operations such as adding and averaging make sense. Ex: height, weight, income,
heart rate, etc.
categorical variables - a characteristic that takes on values that are names or
labels.These are data that cannot be averaged or represented by a scatter plot as they
have no numerical meaning. Ex: The color of a ball, gender, year in school.
data - the raw materials of research, they provide the numbers upon which we perform
statistics
variables - any characteristic that can and does assume different values for the different
people, objects, or events being studied
random assignment - Assignment of individuals to groups by chance (ie, every subject
has an equal chance of being assigned to a particular group).
, independent variable - The variable that is seen as having an effect on the dependent
variable. In experimental designs, the treatment is manipulated.
dependent variabe - The variable that measures the effect of some other variable
treatment group - the group in an experimental investigation that is subjected to the
change in the independent variable
control group - In an experiment, the group that is not exposed to the treatment;
contrasts with the experimental group and serves as a comparison for evaluating the
effect of the treatment.
continuous variable - A variable that can take on any possible value within a range. For
example, weight is a continuous variable because a weight of 152.5 lb makes sense.
discrete variable - number of children is a discrete variable because it can take on only
certain values (0, 1, 2, and so on). A value of 1.2 for children does not make any
conceptual sense.
experimental methods - Research methodologies that involve the manipulation of
independent variables in order to determine their effects on the dependent variables.
correlation methods - research methods that allow researchers to investigate how are
two variables are related
nominal scale - the numbers are simply used as codes representing categories or
characteristics, and there is no order to the categories; they are categorical or
qualitative; usually assigned numbers as codes for computer storage, but they are
arbitrary and do not represent any kind of meaningful order (e.g. gender, ethnicity,
region of residence, marital status)
ordinal scale - measured with numbers representing categories that can be placed in a
meaningful numerical order (e.g., from lowest to highest) but for which there is no
information regarding the specific size of the interval between the different values, and
there is no "true zero." All subjective rating scales are considered ordinal, including
satisfaction scales, ratings of pain or discomfort, symptom checklists to evaluate
psychological states such as depression, and so on.
Likert-scale - variables typically use the following format: "Please rate your level of
agreement with the following statements on a scale of 1 to 5, where '1' is 'strongly
disagree' and '5' is 'strongly agree'." ('strongly like' to 'strongly dislike', 'very satisfied' to
'very dissatisfied')
interval scale - measured with numbers that can be placed in meaningful numerical
order and have meaningful intervals between values because the units of measure are
in equal intervals; it is possible to add and subtract across an interval scale, however,
healthcare
Cochrane Collaboration - develop and disseminate systemic reviews of healthcare
interventions
Florence Nightingale David - produced the first edition of Tables of the Correlation
Coefficient
population - The entire group having some characteristic (eg, all people with
depression, all residents of the United States). Often a sample is taken of the population
and then the results are generalized to that population.
sample - A group selected from the population in the hope that the smaller group will be
representative of the entire population.
parameter - characteristic of a population
statistic - characteristic of a sample
descriptive statistic - numerical or graphical summaries of data, and may include charts,
graphs, and simple summary statistics such as means and standard deviations to
describe characteristics of a population sample
inferential statistics - statistical techniques (e.g., chi-square test, the t test, the one-way
ANOVA) that allow conclusions to be drawn about the relationships found among
different variables in a population sample
quantitative variables - a characteristic that can be measured numerically, a
characteristic with numeric values that have meaning and for which arithmetic
operations such as adding and averaging make sense. Ex: height, weight, income,
heart rate, etc.
categorical variables - a characteristic that takes on values that are names or
labels.These are data that cannot be averaged or represented by a scatter plot as they
have no numerical meaning. Ex: The color of a ball, gender, year in school.
data - the raw materials of research, they provide the numbers upon which we perform
statistics
variables - any characteristic that can and does assume different values for the different
people, objects, or events being studied
random assignment - Assignment of individuals to groups by chance (ie, every subject
has an equal chance of being assigned to a particular group).
, independent variable - The variable that is seen as having an effect on the dependent
variable. In experimental designs, the treatment is manipulated.
dependent variabe - The variable that measures the effect of some other variable
treatment group - the group in an experimental investigation that is subjected to the
change in the independent variable
control group - In an experiment, the group that is not exposed to the treatment;
contrasts with the experimental group and serves as a comparison for evaluating the
effect of the treatment.
continuous variable - A variable that can take on any possible value within a range. For
example, weight is a continuous variable because a weight of 152.5 lb makes sense.
discrete variable - number of children is a discrete variable because it can take on only
certain values (0, 1, 2, and so on). A value of 1.2 for children does not make any
conceptual sense.
experimental methods - Research methodologies that involve the manipulation of
independent variables in order to determine their effects on the dependent variables.
correlation methods - research methods that allow researchers to investigate how are
two variables are related
nominal scale - the numbers are simply used as codes representing categories or
characteristics, and there is no order to the categories; they are categorical or
qualitative; usually assigned numbers as codes for computer storage, but they are
arbitrary and do not represent any kind of meaningful order (e.g. gender, ethnicity,
region of residence, marital status)
ordinal scale - measured with numbers representing categories that can be placed in a
meaningful numerical order (e.g., from lowest to highest) but for which there is no
information regarding the specific size of the interval between the different values, and
there is no "true zero." All subjective rating scales are considered ordinal, including
satisfaction scales, ratings of pain or discomfort, symptom checklists to evaluate
psychological states such as depression, and so on.
Likert-scale - variables typically use the following format: "Please rate your level of
agreement with the following statements on a scale of 1 to 5, where '1' is 'strongly
disagree' and '5' is 'strongly agree'." ('strongly like' to 'strongly dislike', 'very satisfied' to
'very dissatisfied')
interval scale - measured with numbers that can be placed in meaningful numerical
order and have meaningful intervals between values because the units of measure are
in equal intervals; it is possible to add and subtract across an interval scale, however,
