The course aims to familiarize students with the principles and logic of scientific method, by introducing some basic concepts and tools in empirical research. Course objective is to provide a statistical vision of reality: starting with the observed variability of a phenomena, it develops a reflection on the variability and errors inherent to the process of observation and measurement, in order to understand how all the empirical knowledge is actually of sampling nature. It takes place as well as mindset and statistical tools are needed to address the study of any phenomenon.
The first part of the course deals with the analysis of dependence between two variables, and discusses the concept of causality. In the second part of the course, the principles of statistical inference are presented: sample estimation and statistical testing of hypotheses, with the aim of making understood primarily their logic and meaning.
The principles of scientific method and the validity of a research. By formulating the research problem to hypothesis testing. Observation and measurement processes. Types of variables and measurement scales. The concept of distribution.
Transformations of variables. Standardization. Synthetic compound indexes.
The normal distribution. Properties and applications.
Analysis of the dependence between two variables. Frequency of double-entry tables. Conditional frequencies. Independence and association. Indices of association. Dependence on average. Correlation. The linear regression. The method of least squares. Interpretation and evaluation of the model.
Sampling and Estimation. The sampling error. Property of the estimate: precision and accuracy. The bias problem. The confidence interval. How do I determine the sample size ?
Statistical testing of hypotheses. Hypotheses and assumptions. The test statistic and its distribution. The statistical significance. Tests on averages and percentages.
|Capiluppi C.||Appunti di Statistica Sociale||Aracne||2012||978-88-548-5894-7|
|Borra S., Di Ciaccio A.||Statistica, metodologie per le scienze economiche e sociali||McGraw-Hill||2004||8838661626|
The exam consists of a written test (Test), and a following oral exam for the confirmation of the mark.
Written Test (Test)
The written exam takes place in a computer classroom but does not require computer skills: the PC is used only to display the questions and enter the responses, after writing answers/solutions on the paper sheets.
The test is presented as a multiple response test but is a normal written exam, which requires a complete, orderly and readable written answer for all the exercises and questions to which an answer is entered in the computerized questionnaire. Responses to theoretical questions, and even questions that do not require computations, must be adequately explained and justified in writing too.
For the test to be valid, it is necessary to answer 2/3 of the questions (e.g. 20/30). Wrong responses are penalized. Unanswered responses (or with not correct writing) are invalid: any responses that are inserted in the computerized questionnaire but are not explained in the writing, involve a downward revision of the mark, and even its invalidation. Incomplete or incomprehensible written responses are considered invalid.
In the Test there are questions of different types:
- Theoretical questions: assess the level of understanding of statistical and methodological concepts
- Calculation exercises: indices or other statistical measures from numeric data provided in the text
- Theoretical exercises: they require linkages between studied arguments, definitions and properties, or to elaborate algebraic expressions to derive results in symbolic form
- Problems of various kinds: solvable with the help of statistical concepts and properties
Overcoming the Test gives you access to the oral test. The oral examination is only accessible after the test mark is positive. The oral is compulsory for everybody, for the confirmation of the mark.
The oral exam consists of verifying the written responses to the Test for the confirmation of the mark. In the oral exam concepts, measures and statistical indices may, if necessary, be further deepened in terms of understanding and interpreting. During the oral exam it may also be required to perform short, theoretical and computational exercises, of the same type as in the written test.
||Exams Calendar – Shifts and Results