INTRO Flashcards
is the science of conducting studies to collect, organize, summarize, analyze, and draw conclusions from data.
Statistics
a valuable tool in making sense of data in the information age
Statistics
is the development and application of statistical concepts and techniques to biological sciences
Biostatistics
subcategory of statistics, it is statistics applied to biology
Biostatistics
variable in a particular table of data are column-headers
a characteristic or attribute that can assume different values
e.g. age, sex,
Variable
a variable that can have values that are determined by chance
yet to be determined, may still assume different values
e.g. age - ages of participants are yet to be determined
Random Variable
variable with data that is already known because it is already pre-recorded
it is already determined
e.g. date - a non-random variable because date cannot assume different values, date is already determined by convention
Non-random Variable
values that the variables can assume
below the headers in a table of data
can be determined through measurement or observation
Data
collection of data values
table of data
Data
each value in a data set
individual values
Data value or datum
consists of all the subjects that fits the criteria
Population
group of subjects selected from the population
Sample
is a decision making process for evaluating claims about a population
Hypothesis testing
collection, organization, summarization, and presentation of data
describing a situation
merely describing the data
Descriptive Statistics
e.g. census (income, family members) taken from the whole population, survey is the same as census but it only takes a sample from a given population
Descriptive Statistics
EXAMPLE:
Male - 51%
Female - 49%
Descriptive Statistics
generalizing from samples to populations; concept of probability (chance of an event occuring) is used
e.g. When studying the average grade of MLS-1 students in BE-100 with the population of 3725. A sample of 100 students from the population is taken and the average of these students is determined. For as long as the 100 samples are chosen using probabilistic methods, the conclusion taken from this sample is probably true for the whole population.
Inferential Statistics
performing estimations and hypothesis tests;
e.g. testing the claim that the average age of MLS students is 23
Inferential Statistics
determining relationships among variables; and
e.g. relationship between the number of hours studying and the final grade
making predictions
e.g. if there is a relationship between variables, predictions can be made
describing and drawing conclusions from a given data
Inferential Statistics
variables that can be placed into distinct categories, according to some characteristic or attribute
numbers can be used but for labeling only (e.g. 0 for male, 1 for female in an excel sheet)
e.g. sex (male/female), gender, program
Qualitative Variable
are numerical and can be ordered or ranked
e.g. age, grades, blood glucose level
Quantitative Variable
Quantitative Variable: 2 types
discrete variables
continuous variables
assume values that can be counted
e.g. number of participants, number of siblings (counting numbers)
e.g. 1,2,3
discrete variables
can assume an infinite number of values between any two specific values
e.g. arm length/span
e.g. 1.1, 1.2, 1.3
continuous variables
can assume an infinite number of values between any two specific values
e.g. arm length/span
e.g. 1.1, 1.2, 1.3
continuous variables
______________ must be measured, answers must be rounded off because of the limits of the measuring device.
continuous data
Measurement Scales
Nominal Level of Measurement
Ordinal Level of Measurement
Interval Level of Measurement
Ratio Level of Measurement
classifies data into mutually exclusive (nonoverlapping), exhausting categories in which no order or ranking can be imposed on the data
categorical in nature
Nominal Level of Measurement
e.g. religion (Christian, Jewish, Islam, and others) - Christian cannot be Jewish, Jewish cannot be Islam, etc. as it is a nonoverlapping data.
Nominal Level of Measurement