EDA Flashcards
'’The data gathering, a systematic method of
collecting and measuring data’’ from different
sources of information in order to provide answers to relevant questions
Methods of Data Collection
Person who conducts the inquiry
Investigator
Person who helps in collecting information
Enumerator
Three Basic Methods of Collecting Data
● Retrospective Study
● Observational Study
● Designed Experiments
'’Use the population or sample of the historical data’’ which had been archived over some period of time
Retrospective Study
'’Process or population is observed’’ and the
quantities of interests are recorded
Observational Study
'’Deliberate or purposeful changes’’ in the
controllable variables of the system or process is
done
Designed Experiment
'’Method of asking respondents’’ some
well-constructed questions. An efficient way of
collecting information and easy to administer
wherein a wide variety of information can be
collected
Surveys
Where information is collected
Respondent
'’Method is convenient and economical’’ but the
inferences made based on the findings are not so reliable. Also called judgment or subjective sampling
Non-probability Sampling
Most common types of non-probability
sampling
- Convenience Sampling
- Purposive Sampling
- Quota Sampling
'’Researchers use a device in obtaining the information’’ from the respondents which favors the researchers but can cause bias to the respondents
Convenience Sampling
Selection of respondents is ‘‘predetermined according to the characteristics of interest’’ made by the researcher
Purposive Sampling
proportion of groups are considered
Quota sampling
Two Types of Quota Sampling
- Proportional quota sampling
- Non-proportional quota sampling
'’Major characteristics of the population’’ by
sampling a proportional amount of each is
represented
Proportional quota sampling
'’Bit less restrictive’’. A minimum number of
‘‘sampled units in each category is specified
and not concerned’’ with having numbers
that match the proportions in the population
Non-proportional quota sampling
- Every member of the population is ‘‘given an equal chance to be selected’’ as a part of the sample
- Not biased; reliable than non probability
Probability Sampling
Types of Probability Sampling
- Simple Random Sampling
- Stratified Sampling
- Cluster Sampling
- Systemic or Systematic Random Sampling
'’Basic sampling technique’’ where a group of
subjects (a sample) is selected for study from a
larger group (a population)
Simple Random Sampling
'’Obtained by taking samples’’ from each stratum or sub-group of a population
Stratified Sample
Sampling technique where the ‘‘entire population is divided’’ into groups, or clusters, and a random
sample of these clusters are selected
Cluster Sampling
- '’Tool to develop an experimentation strategy’’ that maximizes learning using minimum resources
- Technique needed to identify the “vital few” factors in the most efficient manner and then directs the process to its best setting to meet the ever-increasing demand for improved quality and increased productivity
Design of Experiments (DOE)
Six stages to be carried out for the design of
experiments
● Describe
● Specify
● Design
● Collect
● Fit
● Predict