The Basics Flashcards
What is a variable?
A variable is anything that can vary i.e. changed or be changed
What variable is changed in an experiment?
The independent variable.
In an experiment we are looking for the effect changing the ______ variable has on the _______ variable.
independent
dependent
Name this variable:
The variable that the experimenter manipulates/changes.
Independent variable.
Name this variable:
The variable that the experimenter measures in their experiment.
Dependent variable
Name the independent variable and dependent variable in this study:
The impact of sleep deprivation on performance.
Sleep Deprivation = independent variable.
Performance = dependent variable.
It is assumed that manipulation the ______ variable will have a direct effect on the _____ variable.
Independent
Dependent
Name the scale:
Sorts data into groups or categories
Nominal
Name what scale this data is on?
male, female
nominal
Name the scale:
Ranks data in an order.
Ordinal scale
Name what scale this data is on?
first, second, third
Ordinal
What is the difference between interval and ratio data?
Interval = no true zero ratio = true zero
What data would temperature be?
Interval - goes up and down in equal intervals.
What does true zero mean?
It’s not possible to have negative values.
What data would length and time be?
Ratio - goes up in equal intervals BUT can’t have a negative value.
Continuous or discrete?
Weight and height
Continuous
Continuous or discrete?
Number of seats, number of children.
Discrete! can’t have 2.5 children.
How do you calculate the mean?
Add up all data and divide it by number of items.
How do you calculate the median?
make sure data is in middle and count into the middle.
If there is an even number of items then add up the 2 middle ones and divide by 2.
How do you calculate the mode?
The item that appears most often in a list of data.
define standard deviation
A measure of dispersion of a set of data from its mean.
Calculating the standard deviation:
- Calculate _____
- Subtract each item from the ____
- ____ each of those answers
- ___ all of the ____ and divide it by ______
- then take the ____ ____!
- Calculate Mean
- Subtract each item from the Mean
- Square each of those answers
- Add up all of the squares and divide it by the no. of items.
- Then take the square root!
