Research and Statistics Flashcards
What are the different scales of measurement?
Nominal
Ordinal
Ratio
Interval
What is nominal data?
Numbers are not in a particular order
No real properties they are labels or categories
Quantitative
Ex: hair colour, gender
What is ordinal data?
Group variables into ordered categories
They have a natural order or a rank
Qualitative
Ex: income, education level
What is ratio data?
Has a true zero
Quantitative
Measures variables on a continuous scale
Ex: weight height or age
What is interval data?
Data is measured on a scale
Vales are measures, constants and valued
Has equal intervals between values
Ex: Temperature
What is descriptive statistics?
Describes data
It condenses and organizes data
Also summarizes data
What is Inferential statistics?
allow inferences & generalizations from the sample
to population
What is percentile rank?
Percentage of individuals with a score equal to
or less than the percentile value
What is the mean and how do you find it?
The mean is the average
Find it by adding up all numbers from data and dividing it by how many numbers there are
What is the median and how do you find it?
The mode is the middle number of the data, data has to be in order
What is the mode and how do you find it?
The most repeated number in the data
What is the range?
The difference between the lowest an highest value in the data
What is the standard deviation and how do you find it?
Most common way of describing the spread of a
group of scores
Steps for computing the standard deviation:
1. Figure the variance
2. Take the square root
What is variance?
The expectation of the squared deviation of a random variable from its mean, and it informally measures how far a set of (random) numbers are spread out from their mean.
Find it by multiplying the standard deviation to itself
How do you calculate a z score?
Z is calculated by subtracting the mean
from a score, then dividing by SD
z-scores are useful for comparing distributions with
different means & standard deviations
