MikeLigalig.com

By Jes Tirol
Columnist
The Bohol Chronicle

Proem

A few days ago the Pulse Asia released the results of its October 2007 public opinion survey.  The results for the most corrupt president was: Arroyo = 42%, Marcos = 35%, Estrada = 16%, Ramos = 5%, and Aquino = 1%.  The number of samples taken was 1,200 throughout the Philippines.

Administration’s Reaction

The reaction of the Arroyo administration was to disparage the poll survey results.  The apologists for the Arroyo administration said that the result was only a perception and not a reality; the 1,200 samples could not represent the 84 million Filipinos; and that the survey was paid by the opposition and therefore not reliable.  The apologists for the Arroyo administration missed the correct argument.

Definitions

In order that a poll survey must be credible, it must satisfy the following criteria: accuracy, reliability, and validity.

Accuracy means conformity to a standard rule or measure.  If the standard measure is meter, a measure up to a millimeter is more accurate than a measure up to a centimeter.

Reliability means consistency of result.  Supposing you have a steel tape to measure the distance from A to B; if it will give equal results when the steel tape is cold, normal, or hot, then the steel tape is reliable as a measuring instrument.

Validity means having a high degree of correlation with the criterion.  In other words you are measuring what you purport to measure.  If you want to know the height of Pedro by measuring the height of Juan, then the result is not valid.  To be valid, you must measure Pedro himself to determine his height.
Poll surveys rely on the science of statistics.  If everything is done properly, the results will be credible.

The Question

The question asked was, “In your opinion, which president is the most corrupt in Philippine history?”
The respondents were 1,200 Filipinos with ages from 18 years and above.  According to statistics, the 1,200 samples are already accurate if each of the 84 million Filipinos has an equal chance of being selected as the respondent.  This could be done with proper survey methods.  Therefore the result of the poll survey was accurate.

The Pulse Asia group has been using the same methods and procedures in former surveys.  It has been shown and demonstrated that previous results were correct.  Therefore the result of the survey was reliable and it did not depend on who funded the survey.

The problem is in the aspect of validity.  The presidency of President Marcos was from 1965 to 1986.  Those who were born in 1965 would be 42 years old by now.  Therefore the respondents from 18 to 42 years old or even 50 years old were not yet born or were still too young during the time of President Marcos.  These respondents are in no position to judge the corruption during the time of President Marcos.  Therefore the result of the poll survey was not valid.

Most of the respondents were asked to compare the ZTE scam, Malacañang payola to Governors and Congressmen, Hello Garci Tape, etc. to events during Marcos’ time which they have no knowledge.  It is like asking one million Boholanos who is the more corrupt U.S.A. president, President Bush or President Clinton.  One million samples are very accurate but the result will not be valid because we do not know the situation in the U.S.A.

The Best Argument

The best argument of President Arroyo’s apologist should be the non-validity of the poll survey.  There is such a thing as obsolescence of data.  In the case of perceptions, we remember what is recent and becomes vague about the past.  Asking the respondents about something they do not know or vaguely remember compared to the recent is certainly invalid.


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