Behavioral Science Statistics Chapter I Summary of knowledge points

1, what is the overall? What is a sample?
The whole is a collection of individuals studying all the subjects. The sample is a specific set of individuals who are selected to participate in the study. The sample is expected to represent the overall.

2. Describe the general characteristics, such as the average of the population, is called the parameter .

3. The relationship between the general and the parameters is the same as the relationship between the sample and the statistic .

4, statistical technology is divided into two major categories. What are they called separately? What is the general purpose of each type of technology?
These two categories are descriptive statistics and inferential statistics . descriptive techniques are used to organize, streamline, and summarize data. inferential Techniques Use sample data to make general conclusions about the general.

5, simple definition of the concept of sampling error.
The sampling error is the error or difference between the obtained sample statistic and the corresponding overall parameter.

Variable: A feature or condition that has different values for different individuals.
For example, a variable can be an individual trait, such as height, weight, gender, or personality. When measuring variables, the available letters represent the resulting values, usually denoted by x and Y. For example, researchers can test the sugar intake of a sample of a pre-school child (
X) and the ability to exercise (variable y).

Constant: An attribute or condition that does not change and is the same for each individual.
For example: A study may have examined a 10-year-old child who took the same exam in the same room 2 o'clock in the afternoon. In this study, the age of the subjects, the room, and the time of day were constant.

Measure two variables per individual: The correlation method observes two variables and determines whether there is a relationship between them.

Compare two or more sets of measurements: experimental or non-experimental methods

Experimental Method: A special method of comparing the scores of different groups is called experimental or experimental research , and the purpose of this study is to show the causal relationship between the two variables. Specifically, the experiment assumes that the change of one variable will result in the change of another variable. The experimental method has
two features to separate the experiment from other types of research methods:
1. The manipulation researcher manipulates a variable to change its value from one level to another. The second variable is then observed (measured) to determine whether the manipulation has resulted in a change.

2, the control researcher must control the research situation, so that other useless variables can not affect the need to study the variable relationship.

Definition: in the experimental method , to manipulate a variable and observe or measure another variable, in order to establish a causal relationship between the two variables, the experiment needs to control all other variables so that they do not affect the conclusion.

Problem:
1. A researcher observed that elderly people taking anti-inflammatory drugs regularly had less risk of developing Alzheimer's than those who did not. Is the study using correlation or experimental methods?
This is a related study, and the researchers just observed the variables.

2. What are the two factors required for a study to be an experiment?
First, the researcher has to manipulate one of the two variables in the study, and secondly, to control all other variables that may affect the outcome.

3, the independent variable is the intensity of indoor lighting, because the variable is the degree of frustration of each individual measurement.

Definition of construction and operation
construct : An intrinsic property or feature that cannot be observed directly, but can describe and interpret the behavior.
Operation : is a measurement process (a series of operations) that measures external behavior and uses measurement results as a measure of definition and assumptions. The operation definition has two parts: first, it describes a series of operations to measure the construction. Second, it uses measurement results to determine
It is a righteous construct.

Discrete variables and continuous variables
Discrete variables : consists of different, indivisible categories, and no other values exist between the two adjacent categories. Discrete variables are usually limited to integers.
For example: The number of children in a family, or the number of students attending a class. If you look at the attendance of a class every day, you may get 18 students a day and another 19 students. However, a value between 18 and 19 can never be observed.

Continuous Variables : There is an infinite number of possible values between any of the two observed values, and a continuous variable can be divided into an infinite fractional part.
Two other factors for continuous variables:
1. When measuring continuous variables, two different individuals rarely get exactly the same measurements.
2. When measuring continuous variables, each measurement class is actually an interval, which needs to be defined by the boundary.

Real limit: the bounds of an interval that can be represented as a number on a continuous data line. The real limit for separating the two adjacent values is exactly the midpoint of the two values. Each value has two actual limits. The real limit is the top edge of the interval, and the bottom limit is the bottom of the interval.

Name scale: consists of a series of categories with different names. Classify and label the observed objects, but do not make any quantitative distinctions between observations.
For example, an office or room in a building can be represented by numbers. Room number numbers are just names and do not represent any quantified values.

Sequential scale: consists of a set of categories that are sorted in order. The measurement of the sequential scale sorts the observed objects by size.
For example: small, medium and large drinks in fast food size.

Isometric scale: consists of sorted categories, all of which are exactly the same size, and in the isometric scale, the difference between the numbers on the scale is equivalent to the difference in quantity, however, the scale of the size is meaningless.

Proportion table: is an isometric scale and has an absolute value of 0.
The difference between isometric scale and equal proportion table:
lies in the nature of 0 points. The isometric scale has random 0 points. For example, temperature of 0 degrees Celsius does not indicate no temperature, and will not prevent the temperature continue to decrease. And so the proportion table is determined by 0 points, this 0 point is not arbitrarily determined, but a meaningful value, represents the
Variable without measurement (not present at all)

Problem:
1, a local fast food restaurant has a small, medium and large-scale beverage, measuring the size of the beverage table type is what? Order

2. In a study of facial expression perception, subjects were asked to classify the emotions of people in the photographs as anger, sadness, nausea, fear, or surprise. The expression of emotion is measured by the scale of the name scale.

3. When the measured weight is accurate to 1 kg, what is the actual limit of the value x = 150 kg? 149.5 and 150.5

Statistical symbols

Score: Observing the dependent variable in a study usually results in a value or score for each test. The original score was originally obtained in the study, without a change in the set of data. The value of a particular variable is denoted by the letter x.

Behavioral Science Statistics Chapter I Summary of knowledge points