Psychological Science: Measurement, Uncertainty, and Determinism – Part 2
by Norman Costa
Part 1 of this article can be found HERE.
Other articles in Norman Costa's 'Psychological Science' series can be found HERE.
The [Sad] Story So Far
Few ideas are as fundamental to psychological science, and all science, as the concept of measurement. Science does not exist without measurement. Yet, many psychologists who would identify themselves as scientists do not seem to understand the most fundamental definition of measurement: Measurement is a comparison to a standard. This does not speak well for those who are responsible for scientists-in-the-making at the undergraduate level and especially at the graduate level.
Standards of measurement are inventions of the human mind, they are arbitrary, and they require only consensus and demonstrated utility. Over time, standards are improved, changed, or even discarded. For example, standards of measuring time have evolved from naturalistic observation of the cycles of day and night, to using the oscillating properties of the cesium atom. Standards for measuring psychological depression have evolved from vague and general descriptions to a tallying of specific behaviors that can be observed.
Science is an approach to understanding nature and ourselves that has method and content. Science as method is the systematic observation of phenomena and the recording of data. Without measurement, there is no recording of data from observation. Measuring, comparing to a standard, takes place on many levels from the most simple to the very complex. The most basic comparison to a standard is determining that a phenomenon is present or not present. Other comparisons allow us to determine similarity or dissimilarity. If a decision is made that something is dissimilar to a standard, then we might determine how dissimilar, and in what direction, like more or less. Science as content is the organization of this information into a body of knowledge. For example, we have the science of metallurgy, the science of biology, and the science of verbal learning.
So where is this academic exercise leading us? I thought you would never ask. It is leading us to the next important topic associated with measurement: Error, more specifically, errors of measurement. One of the biggest mistakes that scientific psychology makes, however, is confusing the notion of errors of measurement with Werner Heisenberg's 'Uncertainty Principle.' Do you want to know why physicists laugh themselves silly when psychology presents itself as a science? Do you want to know why many scientists in other fields regard scientific psychology as an oxymoron? Please read on.