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Test 1 Playa
Do IT!
74
Mathematics
Undergraduate 2
09/04/2013

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Term
Use of best clinical evidence in making patient care decisions (We use it everyday!)
Definition
Evidence based practice
Term
Why is EBP important?
Definition
It answers our 3 questions
Term
What are the 3 questions?
Definition
How reliable is the evidence?
What is the magnitude of effects?
How precise is the estimate of effects?
Term
The term for a collection of mathematical methods of organizing, summarizing, analyzing, and interpreting informatino gathered in a study. Not Math.
Definition
Statistics
Term
Why are we studying statistics?*
Definition
To do nursing research so we're able to generate evidence that can contribute to EBP for nurses
Term
something that takes on different values
Definition
Variable
Term
Examples of variables
Definition
height, sex, and respiratory rate vary from one person to the next
Term
The hypothesized cause of, or influence, on an outcome.
Definition
Independent variable
Term
The outcome of interest, hypothesized to depend on, or be caused by, the independent variable
Definition
Dependent Variable
Term
Are the queries researchers seek to answer through the collection and analysis of data
Definition
Research Question
Term
What two components make up a research question?
Definition
Variables and the population (the entire group of interest)
Term
Categories are indivisible, with a finite number of values between two points (must be a whole number)
Definition
Discrete Variable
Term
Discrete Variable example
Definition
Number of siblings (has to be a whole number)
Term
Can (in theory) assume an infinite number of values between two points
Definition
Continuous Variable (think of a clock)
Term
Example of Continuous Variable
Definition
Time elapsed since birth (55.0384 years)
Term
Lowest form of measurement
Numbers are used simply as labels to name categories
Just assigning a number (doesn't show distance cannot be calculated) #'s used as labels
Definition
Nominal Measuring
Term
Uses numbers to designate ordering on an attribute
Conveys some information about amount
But does not indicate distance between values
(ex. degree of pain)
Definition
Ordinal Measurement
Term
Also uses numbers to designate ordering on an attribute and conveys information about amount
Distance between values are assumed to be equal
Averages can be computed
Definition
Interval Measurement (like Temperature)
Term
Uses number to designate ordering, conveys information about amount, distances are equal
And there is a real, rational zero
Averages can be computed
ex. Medication dose
Definition
Ratio Measurement
Term
Based on laws of probability, help researchers draw objective conclusions about a population, using data from a sample
Used to test hypotheses (predictions) about relationships between variables
Definition
Inferential Statistics
Term
Researchers collect their data from a sample of study participants-a subset of the population of interest.
Describes and summarize data about the sample.
Definition
Descriptive Statistics
Term
Statistical procedures for analyzing a single variable at a time.
Definition
Univariate statistics
Term
When three or more variables are included in the same analysis
(researchers may use sex, height, weight, activity level)
Definition
Multivariate statistics
Term
A systematic arrangement of data values, with a count of how many times each value occurred in data set.
Definition
Frequency distribution
Term
Two components of Frequency distribution
Definition
Relative frequencies and cumulative relative frequencies
Term
Relative frequencies
Definition
Percentages
Term
Cumulative relative frequencies
Definition
the percentage for a given score value combined with percentages for all preceding values
Term
Frequency distributions can be constructed for variables measured at any level of measurement but...
Definition
for categorical (nominal level) variables, cumulative frequencies do no make sense. (why? THEY DON'T COMPUTE!)
Term
Frequency Distributions on pages 24-28
How to use and construct it
Definition
Term
Page 29 and 30 read about symmetry, skewness, and kurtosis(especially)
Definition
Term
Wild Code page 31
Definition
Term
Page 32 Construct a chart similar to this on the exam
Definition
Term
Come from the center of distribution of data values, indicating what is "typical", and where data values tend to cluster
Definition
Central Tendency
Called average
Term
Two havles of the distribution folded over in the middle, are identical
Definition
Symmetric Distribution
Term
Peaks are "off center" and there is a tail trailing off for data values with low frewquency
Definition
Skewed Distribution
Term
Degree of pointedness of flatness of the distribution's peak
Definition
Kurtosis
Term
Very thin, sharp peak
Definition
Leptokurtic
Term
Flat Peak
Definition
Flat Peak
Term
Neither pointy of flat
Definition
Mesokurtic
Term
What are the three alternative indexes?
Definition
The mode, median, and mean
Term
The score value with the highest frequency: the most "popular" score
Definition
Mode
Term
Advantages of the Mode
Definition
Can be used with data measured on any measurement level (including nominal level)
Easy to Compute
Reflects an actual value in the distribution so it is easy to understand
Useful when there are 2+ popular scores (i.e. multimodal distributions)
Term
Disadvantages of Mode
Definition
Ignores most information in the distribution
Tends to be unstable (value varies from one sample to the next)
Sometimes there may not be a mode
Term
The score that divides the distribution into two equal halves
Definition
The Median
Term
The median advantages
Definition
not influenced by outliers
Good index of what is typical when distribution is skewed
Easy to "compute"
Appropriate when data are ordinal level
Term
The Median Disadvantages
Definition
Does not take actual data values into account-only an index position
Value of median not necessarily an actual data value, so it is more difficult to understand than mode
Term
The arithmetic average
Most frequently used measure of central tendency-usually preferred for interval and ratio-level data
Definition
the mean
Term
N
Definition
number
Term
Equation
Definition
M = (Sigma)X \ N

X=actual data values
Sigma=Sum of numbers
Term
The Mean advantages
Definition
Sum of deviations above the mean always exactly balances those below it
Does not ignore any information
The most stable index of central tendency
Many inferential statistics are based on the mean
Term
the mean disadvantages
Definition
Sensitive to outliers
Gives a distorted view of what is "typical" when data are skewed
Value of mean is often not an actual data value
Term
In normal distribution all three indexes (mean median and mode)
Definition
Coincide
Term
A heterogeneous distribution
Definition
High Variability
Term
A homogeneous distribution
Definition
Low Variability
Term
The difference between the highest and lowest value in the distribution
Definition
Range
Term
Range Adv.
Definition
Easy to compute
Readily understood
Communicates information of interest to readers of a report
Term
Range Disad.
Definition
Depends on only two scores, does not take all info. into account
sensitive to outliers
tends to be unstable-fluctuates from sample to sample
Influenced by sample size
Term
Based on quartiles
The range of scores within which the middle 50% of scores lie
Definition
The Interquartile Range
Term
Lower quartiles (Q1)
Definition
Point below 25%
Term
Upper Quartile (Q3)
Definition
Point below which 75% score lies
Term
IQR=
Definition
Q3-Q1
Term
IQR Adv.
Definition
Reduces influence of outliers and extreme scores in expressing variability
Uses more information that the range
Important in evaluating outliers
appropriate as index of variability with ordinal measures
Term
IQR Disad
Definition
Is not particularly easy to compute
Is not well understood
Does not take all values into account
Term
An index that conveys how much, on average, scores in a distribution vary
Definition
Standard Deviation (SD)
(Like IQ's)
Term
SD=
Definition
Sigma x^2 \ (N-1)
Term
The SD indicates the average amount
Definition
of deviation scores from the mean
Term
Standard deviation has to be
Definition
Symmetrical
Term
SD Adv.
Definition
Takes all data into account in describing variability
Is more stable as a measure of variability than the range or IQR
Lends itself to computation of other measures often used in inferential statistics
Is helpful in interpreting individual scores when data are distributed approx. normally
Term
SD Disad
Definition
Can be influenced by extreme scores
Not as "intuitive" or easy to interpret as the range
Term
An important variability concept in inferential statistics, but not used descriptively
Definition
Variance
Term
Page 13 chapt. 2 pg 13 look at chart
Definition
Term
There are also descriptive statistics to describe individual scores (ie their relative standing or position in a distribution: percentile ranks and standard score)
Definition
Relative Standing
Term
A one-hundreth of a distribution
Definition
Percentile
Term
Read page 5-6
pg 44
Definition
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