CE 190- Chapter 1

63問 • 2年前

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Collections of observations, such as measurements, genders, or survey responses

Data

The science of planning studies and experiments; obtaining data; and organizing, summarizing, presenting, analyzing, and interpreting those data and then drawing conclusions based on them.

Statistics

The complete collection of all measurements or data that are being considered. Typically, a ________ is the complete collection of data that we would like to make inferences about.

Population

The collection of data from every member of a population

Census

A subcollection of members selected from a population

Sample

2 types of data

Parameter, Statistic

a numerical measurement describing some characteristic of a population

Parameter

a numerical measurement describing some characteristic of a sample

Statistic

are the characteristics of the individuals within the population.

Variables

Variables can be classified into two groups:

Qualitative, Quantitative

variables allow for classification of individuals based on some attribute or characteristic.

Qualitative

variables provide numerical measures of individuals.

Quantitative

2 types of quantitative variables:

Discrete, Continuous

is a quantitative variable that has either a finite number of possible values or a countable number of possible values.

Discrete

is a quantitative variable that has an infinite number of possible values that are not countable.

Continuous

The list of observed values for a variable is _________.

Data

Gender is a _________.

Variable

the observations male and female are ______.

Data

if the values of the variable name, label, or categorize. In addition, the naming scheme does not allow for the values of the variable to be arranged in a ranked or specific order

Nominal

if it has the properties of the nominal level of measurement, however, the naming scheme allows for the values of the variable to be arranged in a ranked or

Ordinal

if it has the properties of the ordinal level of measurement and the differences in the values of the variable have meaning. A value of zero does not mean the absence of the quantity. Arithmetic operations such as addition and subtraction can be performed on values of the va

Interval

if it has the properties of the interval level of measurement and the ratios of the values of the variable have meaning. A value of zero means the absence of the quantity. Arithmetic operations such as multiplication and division can be performed on the values of th

Ratio

Statistical and Critical Thinking

Identify The Research Objective, Collect The Data Needed, Descrive The Data, Perform Inference, Making Conclusions

A researcher must determine the questions

Identify The Research Objective

Vital the statistical process

Collect The Data Needed

allow the researcher to obtain an overview

Descriptive Statistics

Apply the appropriate techniques

Perform Inference

The final step in our statistical process

Making Conclusions

Levels of measurement

Nominal, Ordinal, Interval, Ratio

are driven by the data that we collect.

Statistical Methods

We typically obtain data from two distinct sources:

Observational Studies, Designed Experiments

observe and measure specific characteristics without attempting to modify the individuals being studied

Observational Study

apply some treatment and then proceed to observe its effects on the individuals.

Experiment

use or called for people being experimented

Subjects

is potentially a major problem with observational studies.

Confounding

effects of two or more are not separated

Confounding

cause of confounding

Lurking Variable

is an explanatory variable that was not considered in a study, but that affects the value of the response variable in the study.

Lurking Variable

Types of observational studies

Cross-Sectional, Case-Control, Cohort

collect information about individuals at a specific point in time or over a very short period of time.

Cross-Sectional Studies

retrospective studies, meaning that they require individuals to look back in time or require the researcher to look at existing records.

Case-Control Studies

-first identifies a group of individuals to participate in the study. -observed over a long period of time.

Cohort Studies

is the process of using chance to select individuals from a population to be included in the sample

Random Sampling

-The most basic sample survey design. -equally likely chance of occurring.

Simple Random Sampling

is obtained by separating the population

Stratified Sampling

Non overlapping groups

Strata

random number between 1 and k.

Systematic Sampling

group of individuals.

Cluster Sampling

are inappropriate, in which the individuals are not randomly selected.

Non-Random Sampling

the individuals are easily obtained and not based on randomness

Convenience Sampling

Convenience Sampling are also called

Voluntary Response Samples

sample are not representative of the population,

Bias

ends to favor one part of the population over another.

Sampling Bias

-one segment of the population is lower -result of sampling bias

Undercoverage

selected individuals did not response

Nonresponse Bias

answers on a survey do not reflect the true feelings of the respondent

Response Bias

Response bias can occur in a number of ways

Interviewer Error, Misrepresented Answers, Wording Of Questions, Ordering Of Questions, Type Of Question, Data-Entry Error

controlled study

Designed Experiment

combination of factors

Treatment

baseline treatment

Control Group

nondisclosure of the treatment

Bindings

the subject does not know the treatment she is receiving

Single-Blind Experiments

neither experimental unit or researcher know

Double-Blind Experiments

Xeth LE 5

Mharvie Nagal · 39問 · 2年前

Xeth LE 5