PSYC 210 setting up for midterm

what are variables

variables can be anything that can take on more than one value

What is an independent variable (IV) and what is another name for it

it is also called a predictor

it is a variable that is manipulated

what is a dependent variable (DV) and what is another name for it

it is also called a response

its a variable that is measured

what is a Quasi-independent variable

it is a variable that cannot be manipulated (it already exists)

examples are age, gender, a preexisting medical condition, eye colour

what is an extraneous/confounding variable

it is a variable that we are not investigating but affecting the results

population vs sample

population is the total pool a sample is a few pieces from that pool

what is statistical inference

the formal process of using data from a small sample to make educated guesses or draw conclusions about a much larger population.

• Inferential statistics is the toolkit (the spoon, the recipe, the rules of tasting).

• Statistical inference is the actual act of tasting that one spoonful and declaring, "The whole pot needs more salt."

what is an experimental designs characteristics

manipulation, randomization, and comparison/control

what is an experimental design

a carefully planned test where a researcher changes one specific thing to see if it directly causes a change in something else.

example Imagine you invent an energy drink called RocketJuice and want to prove it causes people to run faster.

what is a quasi-experimental design

a research method that looks a lot like a true scientific experiment, but it lacks one crucial feature: random assignment it uses preexisting groups and use the information that is already there

what are the characteristics of a quasi-experimental design

includes a quasi-independent variable (cannot be manipulated) and/or (2) lacks a comparison/control group

what is a correlational design

looking at the relationship between two or more variables without any manipulation remember correlation does not equal causation

what is a notation

it is the way in which we symbolize aspects of data, such as variables, scores/measurements/values, etc.

• upper or lower case letters

• numerical subscript

• general index

what is “X“

it represents the variable

what is “i“

it represents the observation

what does X_{i mean}

it represents the variable for observation i

what does this image mean

find the sum of numbers between 0 and 2 so you start at 0 and stop at 2

what is rule 1 for summing a constant

number of times it appears multiplied by the constant

the key idea is to count how many times c appears, then multiply by c

what is a constant

it is a value that does not change

what is the rule for summing cX

cX is a constant multiplied by a variable

because the constant is constant and the variable can change for each operation you add the values of X then multiply by c

what is the distributive laws over addition and subtraction

for example if you have E(X_i + Y_i - c) you sum the X’s + sum the Y’s - sum the constant

summation CAN distribute over + and -

what is the non distributive laws over multiplication and division

sum of products does not equal product of sums for example product of sums is E(X_i x Y_i) which multiplying the the products and adding it with the other observation and product of sums is (E X_i)(E Y_i) which is adding the products and multiplying the result between the observations

what is descriptive statistics

the branch of statistics that simply summarizes, organizes, and describes the data you already have

example if you have soup and you take a spoonful You aren't guessing about the rest of the pot; you are just saying, "This spoonful has three carrots, two peas, and is 60 degrees Celsius.descriptive statistics is just describing exactly what is on your spoon.

what is inferential statistics

a branch of statistics that uses data from a small, random sample to make predictions, test claims, or draw conclusions about a much larger [population]

example: Imagine you are cooking a massive pot of soup for a party. You cannot drink the entire pot just to find out if it needs more salt. Instead, you use a small spoon to taste one sip.

what is the difference between data and raw score

Data is a broad collection of information or facts, while a raw score is a single, specific, and unaltered measurement from that collection

by definition how is sample related to population

a smaller, manageable subset drawn from a larger population

what are three commonly used research methods in behavioural science

experimental research, observational studies, and survey research

how do you find the median

line all numbers up from lowest to highest and find the number exactly in the center of the number line if there are two then you find the mean of those two numbers

how do you find the mode

you look for the number that shows up the most in the sequence it helps to line them up

how do you find the mean/average

you add all the numbers up and divide by the number of numbers

how do you find the range

you find the lowest number in the set and you subtract it from the largest number in the set