Psychstats Midterms

• In a true experiment, an independent variable is manipulated and its effect on some dependent variable is studied.
• The term statistics has its origin in Latin word STATUS , Italian word STATISTA or German term STATISTIK , all meaning POLITICAL STATE .
• In ancient periods, the beginning of statistics was made to meet the administrative needs of the state.
• In modern times, statistics is not related to the administration of the state alone, but it has close relation with almost all those activities of our lives which can be expressed in quantitative terms.
• Statistics is the science concerned with developing and studying methods for collecting, analyzing, interpreting and presenting empirical data.
• Statistics involves developing and studying methods for collecting, analyzing, interpreting and presenting empirical data.
• A variable should be contrasted with a constant, which, of course, does not have different values at different times.
• Scientific research may be divided into two categories: observational studies and true experiments.
• Data are facts or set of information gathered or under study.
• In observational studies, no variables are actively manipulated by the investigator, and hence observational studies cannot determine causality.
• True experiments attempt to determine whether changes in one variable cause changes in another variable.
• An example of a Continuous Variable is interest rate in %.
• An example of a variable is the mathematical constant; it always has the same value (3.14 to two-decimal-place accuracy).
• Parameter estimation research is conducted on samples to estimate the level of one or more population characteristics.
• In correlational research, the investigator focuses attention on two or more variables to determine whether they are related.
• Examples of Qualitative Variables/data include gender, major, religion, color of a car, rating.
• Dependent Variables and Independent Variables are used in scientific research.
• A Discrete Variable can assume only a finite or countable number of values (Exact).
• An example of a Discrete Variable is class size - # of students.
• Quantitative Variables/data are numerical in nature and therefore meaningful arithmetic can be done.
• Variable is a characteristic that changes or varies over time and/or for different individuals or objects under consideration.
• Naturalistic observation research aims to obtain an accurate description of the situation being studied.
• Qualitative Variables/data are attributes which cannot be subjected to meaningful arithmetic and produce data (categorical data) that can be categorized according to similarities or differences.
• A Continuous Variable can assume the infinitely many values.
• Types of Variables/Data: Qualitative Variables/data and Quantitative Variables/data.
• Statistical techniques are important in both kinds of research.