# Stat II Chapter 1 Quiz Flashcards

## Terms

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Descriptive Statistics
Mathematical procedures for summarizing and describing the charecteristics in a set of data.
Inferential Statistics
Mathematical procedures for drawing interferences about charecteristics of a population, based on what is observed in a sample from that population.
Population
All of the cases in which a researcher is interested; a (usually very large) group of people, animals, objects, or responses that are alike in at least one respect.
Sample
Any subgroup of cases drawn from a clearly specified population.
Statistic
A numeric quantity that summarizes some charectertistic of a sample.
Summation Sign
A mathematical symbol that represents the sum of a set of numbers.
Parameter
A numerical quality that summarizes some charecteristic of a population.
Why Study Statistics?
Because at a 1939 conference in Boulder, CO, the word psychologist was defined as someone who was a scientist and a practioner.
What are three important reasons why a knowledge of statistics is essential for anyone majoring in psychology, sociology or education?
1. To understand professional literature.
2. To understand the rationale underlying research in the behavioral sciences.
3. To carry out behavioral science research.
What is the difference between descriptive and inferential statistics?
Descriptive statistics are used to summarize something, such as grades using GPA. Inferential statistics area little more broad, such as making generalizations for a group or estimating the probability of an outcome.
Why must behavioral science researchers use inferential statistics?
Because they want to know what is happening in a population, but they cannot measure the whole population, so they use inferential statistics to make generalizations for a sample of the entire population.
What is the difference between a population and a sample?
A population is a large group of people, animals, or objects with at least one similar trait, however, when researching if a population is too large to work with, a random sample may be used that is smaller, but proportionate to the population.
Why is it important to specify clearly the population from which a sample is drawn?
Because you need to make sure that the sample accurately represents the entire population.
What is the difference between a parameter and a statisic?
A parameter summarizes a charecteristic of a population and a statistic summarizes a charecteristic of a sample.
Why is summation notation used by statistaticians?
To represent the sum of a set of numbers, basically as a short hand.
What are the eight rules of summation notation? (Look at card.)
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