Statistics chapter 1 Flashcards Table View


1. Collecting data (questionaires, recording numbers, surveys)
2. Describe Date (average - arithmetic mean, graphs, tables, measures of central tendency)
3. Analyze Data - what we will be doing in statistics
4. Interpret Date - How can you use this analyzed data, descisions made from it
set of all individuals of interest in a particular study.
scientific research begins with a general question about a specific group of individuals.
Sample Set of individuals selected from a population, usually intended to represent the population in a research study.
A characteristic or condition that changes or has different values for different individuals.
Ex: height, gender, personality
Data (plural) are mesurements or observations
Data Set A collection of measurements or observations
Datum (singular)
is a single measurement or observation
Commonly called: Score or raw score
What is Datum usually called?
Score or raw score
(refer to a population or samples of scores)
is a value, usually a numerical value, that describes a population. A parameter may be obtained from a single measurement or it may be derived from a set of measurements from the population.
it is a known value. measure of CENTRAL TENDENCY (average) SPREAD of the data for population. BUT not exact - don't have HOLE population
How are Parameters obtained? A parameter may be obtained from a single measurement or it may be derived from a set of measurements from the population.
StatistiC a value, usually a numerical value, that describes a sample. A statistic may be obtained from a single measurement, or it may be derived from a set of measurments from the sample.
How is a Statistic obtained? A statistic may be obtained from a single measurement, or it may be derived from a set of measurments from the sample.
Every population parameter has a corresponding______ ______. Sample Statistic
Much of the book is concerned with...? the relationship between sample statistics and the corresponding population parameters.
Descriptive Statistics
statistical procedures used to summarize, organize, and simplify data.
The first 2 steps of statistics - 1. Collecting Date, 2. Describe Data - organize/ summerize
Inferential Statistics
constist of techniques that allow us to study samples and then make generalizations about the populations from which they were selected
The 2 LAST steps of statistics definition. 3. Analyze data, 4. Interpret data
What are the problems with using sampling? samples provides only limited information about the population. Although samples are generally representative of thier populations, a sample is not expected to give a perfectly accurate picture of the whole population.
Sampling Error is the discrepancy, or amount of error, that exists between a sample statistic and the corresponding population parameter.
What is the purpose of ingerential statistics? to answer the question.
A characteristic that describes a population, such as the population average, is called a __________ Parameter
Relationship between a population ans a _____ parameter
relationship between a sample and a ______ Statistic
Statistical techniques are classifies into 2 general categories. What are they, what are there purpose?
Descriptive statistics - intended to organize, simplify and summarize data
Inferential techiques- use sample data to reach general conclusions about populations
correlational method two variables are observed to determine whether there is a relationship between them
Manipulation the researcher manipulates one varible by changing its value from one level to another. a second variable is observed (measured) to determine whether the manipulation causes changes to occur.
Control researcher must exercise some control over the research situation to ensure that other, extraneous variables do not influence the relationship being examined
Researchers must consider 2 general categories of variables, what are they?
Participant variables - age, gender, intelleigence ex must be the same, can not differ from one group to the other.
Environment variables - lighting, time of day, weather conditions. cannot differ from one group to the other.
3 basic techniques to control other variables.
1. Random assignment - each participant has an equal chance of being assigned to each of the treatment conditions.
2. matching - to ensure equivvalet groups or equivalent environments
3. holding them constant - ex. experiement only uses 10 year old boys (holding age constant)
Independent variable variable that is manipulated by the researcher.
Dependent variable variable that is observed in oreder to assess the effect of the treatment.
Control condition individuals in a control condition do not recieve the experimental treatment. they either receive no treatment or reviece a placebo.
Experimental condition individuals in the experiemental condition do receive the experimental treatment
Quasi-independent variable a nonexperimental study, in 'independent variable' that is used to create the different groups of scores
What 2 elements are necessary for a research study to be an expereiment?
1. the researcher must manipulate one of the two variables being studied
2. all other variables that might influence the results must be controlled
Constructs internal attributes or characteristics that cannot be directly observed but are sueful for describing and explaining behaviour
Operational definition identifies a measurement procedure for measuring an external behavior and suses the resulting measurements as a definition has 2 components, 1. it describes a set of operations for measuring a construct. 2. defines the construct in terms of the resulting measurements
Nominal Scale
NAME: consists of a set of categories that have different manes. measurments on a nominal scale label and categorize observations ut do not make any quantitative distinctions between observations. ex. You vote for, NDP, Conservatives, Liberal = NO NUMBERS
EX. Rate someone1, 2, 3, 4, 5 = if 4, this means he's a little bit perfect if 5 is perfect, BUT 4 is not a number, it is a NAME: 'little bit perfect'
Ordinal Scale
ORDER: consists of a set of categories that are organize in an ordered sequence. Measurements on an ordinal scale rank observations in terms of size or magnitude
ex. Horse race, 1st, 2nd, 3rd place. you know who is ahead of who BUT Don't No by how much
Interval scale
consists of ordered categories that are all intervals of exactly the same size. equal differences between numbers on an interval scale reflect equal differences in magnitude. However, the zero point on an interval scale is arbitrary and does not indicate a zero amount of the cariable being measured.
ex. 20, 10, 0 degrees. No the distance between. 10 degrees is 10 degrees hoter than 0 degrees. BUT cannot no that 20 degrees is twice as hot as something. Zero point is arbitrary
Ratio scale
WEIGHT: an interval scale with the additional feature of an absolute zero point. with a ratio scale, ratios of numbers do reflect ratios of magnitude
EX. 200lb, 100lb, 0 lb. Know the distance between. Can say 200 lb man is twice as heavy as a 100 lb man because you know that 0 is the absence of weight (an absolute).
The local fast food offer small, medium and large drinks...what kind of scale is used to measure the size of the drinks? Ordinal
_______measures the aptitude on the SAT scale... Interval
emotional expression is measured on a ___scale. Nominal
Researcher studies the fators that determine how many children couples decide to have. the variable, number of children is a ____variable Discrete
discrete variable
WHOLE NUMBERS or whole responses. consists of separate indivisible categories. no values can exist between two neighbouring categories.
EX. Male or Female. Right or Left. 4 Dogs NOT 1.35 dogs. There is NOTHING inbetween these WHOLE numbers. ex. 5'2" tall NOT 5.1876899' tall
# of children in a family or # of students in a class
continuous variable
there are an infinite number of possible values that fall between any 2 observed values. it is divisible into an infinite number of fractional parts
Ex. NOT 5'2" tall...5.80899 feet tall. Get VERY accurate. INFINATE - continued forever = no "true" height because it will keep changing and can keep measuring it to a more procise measure.
Real Limits the boundaries of intervals for scores that are represeented on a continuous number line. The real limit separating two adjacent scores is located exactly halfway between the scores. Each scare has two real limitis.
Upper Real Limit is at the top of the interval.
Lower Real Limit is at the bottom of the interval.
The concept of real limits aplies to any measurement of a ______ _______, even when the score categories are not ____________ _____. Continuous variables, whole numbers.
What does X represent X is the scores for a particular variable - represented by the letter X
N is... number of scores in a population
n is... number of scores in a sample
sideways M is... SUMMATION, add scores, it is the sum of a set of scores
Sidways MX is....
"the sum of scores" Add all scores for variable X
EX. a set of quix scores - add them all up
Mathamatival Operations- what is the order?
1) Any calculation contained within parenthese
2) Squaring (or raising to other exponents)
3) Multiplying/dividing - a series of multiplying and dividing should be done from right to left
4) SUMMATION using M notation
5) any other addition or subtraction
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