1) Chapter 1: Basics Flashcards
Basics of Statisitics:
The main purpose is to create relevant?
To obtain main purpose, statistics uses methods of?
Statistical Analysis?
population, sample, subject?
- To create relevant data. The observations gathered on the characteristics of interest are collectively called data.
- Specifically, statistics provides methods for:
- Design. Planning how to gather data for research studies
- Description’. Summarizing the data. Summarized data as tables, graphs, pictures is part of descriptive statistics.
- Inference. Making predictions based on the data
- Description and Inference are parts of statistical analysis.
Population total set of entities >> Sample is a subset of population >> Subject is observed entity.
Inferential Statistics?
Inferential statistics provide a prediction about the larger population using the
sample data.
Parameters and Statistic?
Statistic is numerical summary based on sample data.
Parameters is numerical summary based on population data.
- Discrete and
- Continuous
Variables?
- ’ The number of…’ when it is possible to form a set of separate numbers.
- Hours, height, weight (8.629 hours)
Types of a random sample?
1 type
Simple random sampling.
- Sampling frame
- Number the subjects
- Generate a set of these numbers randomly
- Sample the subjects whose numbers were generated
How to collect data from a sample?
3 methods
- Sample surveys (GSS) - interview, telephone, questionnaire
- Experiment
- Conditions: treatment - Observational Study
- Merely observe subjects without any manipulations.
Probability sampling methods?
3 types
- Systematic Random sampling.
- Using only one random number. N=30.000 n=100 k=30.000/100= 300. Random number 105. 105+300=405+300= 705 and so on. - Stratified Random sampling
- Divides the population into separate groups, called strata, and then selects a simple random sample from each stratum. - Multistage sampling.
- Random sample of Clusters» random samples out of clusters» Systematic random sample of every sampled region out of cluster» Within each house selected, select one adult at random for the sample.
Summarizing data using Descriptive Statistics:
- Quantitative variables?
- Key features of quantitative variables?
1) Quantitative variables are showing the number of times various outcomes occurred
2) Key features:
● The center of Data - Typical observation
● The variability of data - the spread around center