Engineering Data Analysis

Topic 1: Data Collection And Conducting Surveys

Data collection

First step in conducting data analysis

Data gathering or data collection

a systematic method of collecting and measuring data from different sources of information in order to provide answers to relevant questions

questionnaires

interviews

experimentations

documents and records

tests or examinations

Examples of data gathering instruments used in data collection

Investigator

The person who conducts the inquiry

Enumerator

The one who helps in collecting information

Respondent

information is collected from a________.

retrospective study

observational study

designed experiment

three basic methods of collecting data in the field of engineering

Retrospective study

uses the population or sample of the historical data which had been archived over some period of time

Observational study

In a _________, process or population is observed and disturbed as little as possible, and the quantities of interests are recorded

Designed experiment

In a ________, deliberate or purposeful changes in the controllable variables of the system or process is done. The resulting system output data must be observed, and an inference or decision about which variables are responsible for the observed changes in output performance is made

Surveying

 a method of asking respondents some well-constructed questions. It is an efficient way of collecting information and easy to administer wherein a wide variety of information can be collected.

face-to-face interviews

self-administered through the use of questionnaires

Surveys can be done through …..

• Determine the objectives of your survey

• Identify the target population sample

• Choose an interviewing method

• Decide what questions you will ask in what order, and how to phrase them.

• Conduct the interview and collect the information.

• Analyze the results by making graphs and drawing conclusions

Steps in designing a survey

Determine the objectives of your survey

In what step does “what questions do you want to answer” included?

Identify the target population sample

In what step does “Whom will you interview? Who will be the respondents? What sampling method will you use?” included?

Choose an interviewing method

In what step does “face-to-face interview, phone interview, self administered paper survey, or internet survey” included?

Sampling

process of selecting units (eg. people, organizations) from a population of interest

Sample

must be a representative of the target population

Target population

 is the entire group a researcher is interested in, the group about which the researcher wishes to draw conclusions

Non-probability sampling

Probability sampling

two ways of selecting a sample

judgment or subjective sampling

Non-probability sampling is also called _____________

Non-probability sampling

This method is convenient and economical but the inferences made based on the findings are not so reliable

convenience sampling

purposive sampling

quota sampling

 most common types of non- probability sampling

Convenience sampling

the researcher use a device in obtaining the information from the respondents which favors the researcher but can cause bias to the respondents

Purposive sampling

the selection of respondents is predetermined according to the characteristic of interest made by the researcher

 Proportional quota sampling

Non proportional quota sampling

 Two types of quota sampling

Proportional quota sampling

In___________ the major characteristics of the population by sampling a proportional amount of each is represented

Non-proportional quota sampling

a bit less restrictive than proportional quota sampling

Non-proportional quota sampling

a minimum number of sampled units in each category is specified and not concerned with having numbers that match the proportions in the population

Probability sampling

every member of the population is given an equal chance to be selected as a part of the sample

simple random sampling

stratified sampling

cluster sampling

Examples of probability techniques

Simple random sampling

the basic sampling technique where a group of subjects (a sample) is selected for study from a larger group (a population). Each individual is chosen entirely by chance and each member of the population has an equal chance of being included in the sample

Stratified sample

obtained by taking samples from each stratum or sub-group of a population. When a sample is to be taken from a population with several strata, the proportion of each stratum in the sample should be the same as in the population

Cluster sampling

 a sampling technique where the entire population is divided into groups, or clusters, and a random sample of these clusters are selected. All observations in the selected clusters are included in the sample

Design of Experiments (DOE)

 a tool to develop an experimentation strategy that maximizes learning using minimum resources

Design of Experiments (DOE)

widely and extensively used by engineers and scientists in improving existing process through maximizing the yield and decreasing the variability or in developing new products and processes

vital few

Design of Experiments (DOE) is a technique needed to identify the _________ 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.

1) Describe

2) Specify

3) Design

4) Collect

5) Fit

6) Predict

Six stages to be carried out for the design of experiments

Describe

identifying objectives and important factors that is relevant in carrying out the experiment

Specify

determining the best setting in accomplishing the objective of the experiment

Design

design model process that will be used in the experiment and conduct initial run test

Collect

generate and record data runs

Fit

validate the result of trial thru conducting additional run to confirm if objectives were achieved

Stratified sampling

Finding out a favourite soap opera from different age categories of people in a year group is an example of?

Simple random sampling

Using a random number generator to select students in a class to complete a task is an example of?

Snowball sampling

Marice determines her respondents by asking people as to who would be most suited for her study. Through this, she is referred from one respondent to the other. What type of non-probability sampling has been utilized?