The Volokh Conspiracy

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How Content Analysis Can Measure Health and Safety in Occupational Licensing Requirements

Should a quantitative analysis of the language of textbooks be methodologically controversial?


In my recent paper "Regulating Glamour," I found that only about 25% of the required training for barbers and cosmetologists is related to health or safety. This is a notable claim; readers may want to know more about the method used to derive it. In this post, I discuss the methods used to produce these findings. The article's method rests on what is called content analysis—to oversimplify, my content analysis rested on counting and analyzing the words and sentences in textbooks used by barbers, cosmetologists, and manicurists.

Let me begin with an explanation of state-required curricula for appearance professionals. Just as high school degrees in many states require a certain number of hours of instruction under state law in English, math, history, and so forth, in many states a degree in cosmetology requires a certain number of hours of instruction in such fields as haircutting, shampooing, hair coloring, and chemically relaxing the hair.

Consider the following two instances of the way that health and safety instruction might be included in the fields of a cosmetology curriculum. When cosmetology students are taught how to give haircuts, they are typically taught how to do so safely (for instance, you must clean and disinfect your instruments, or else you may spread disease); when cosmetology students are taught how to chemically relax hair, they are typically taught how to do so safely (for instance, you must not apply certain kinds of chemical relaxers to the hair if it has previously been colored with metallic salts, or else you may cause dangerous chemical reactions and hair breakage).

The Article's calculations rely on a survey of each relevant chapter of three leading textbooks for appearance professionals that describe health and safety rules, practices, and concerns (the three textbooks I used occupy roughly three-quarters of the student market): it is probably uncontroversial to say that the health and safety rules and concerns that the textbooks describe for haircutting are sparse, brief, often intuitive, and easy to remember; however, this probably is not true for the health and safety concerns that the textbooks describe for chemical hair relaxers, which are relatively extensive and abstruse (and, in a few instances, a little alarming: in some circumstances, misuse will cause hair to issue smoke or even to melt). This highlights what perhaps is obvious: the curricula for different fields can be expected to contain different amounts or proportions of instruction that are relevant to health and safety.

How might one determine what portion of training in some particular field is related to health and safety? This Article's methodology includes a content analysis of the latest edition of these textbooks so as to derive a health and safety rating for each field. In each case, I measured the portion of the text that pertained to health and safety. (The assumption here is that the relevant text about some given field is a reasonably complete account of the formal and theoretical aspects that students need to learn about that subfield; perhaps a critic of this assumption might argue that there is no significant relationship between the textbooks' content and what prospective appearance professionals must learn, but that critic would likely find it difficult to explain why so many professional schools assign and require a textbook.)

This measurement typically resulted in a ratio: for instance, if a field was entirely described in a particular chapter or subchapter in one of the textbooks, a figure based on the length of the health- and safety-related concerns and instructions in that text was then divided by another figure based on the length of the field's entire text. So, for instance, given a chapter that pertained to a particular field, if one-fifth of that chapter pertained to health and safety issues, I gave it a health and safety rating of 20%.

Assuming that this is a reasonable methodology for providing an estimate of the health and safety portion of a personal appearance curriculum, it follows that the number of hours of health and safety training for any given jurisdiction and subfield can be calculated: one simply multiplies the health and safety rating by the number of hours that the jurisdiction devotes to training in that subfield to arrive at an estimate of training, as expressed in hours, in health and safety for that subfield. For instance (and to put it less formally), this method finds that health and safety concerns constitute just over 3% of the relevant textbook's haircutting chapter. The significance of this is that if a jurisdiction's cosmetology curriculum requires 100 hours of haircutting instruction, this Article's methodology implies that just over 3% of the haircutting instruction—or 3 hours—is devoted to health and safety training.

This quantitative approach permits the calculation of the estimated portion of health and safety training in the required set of personal appearance subfields for any given profession and jurisdiction: this calculation is performed by summing all the hourly health/safety requirements for that jurisdiction that are already derived, then dividing that sum by the total number of hours that the jurisdiction requires.

Although one could argue that a significant degree of health and safety training is not well-measured by content analysis, given that such training sometimes takes place while performing appearance services rather than by learning abstract propositions, that argument would have some eyebrow-raising implications for the training of appearance professionals. For instance, cosmetology educators would presumably affirm that all students at their schools receive sufficient training to perform any particular procedure safely before those students are ever asked to perform that same procedure on a human volunteer; such an affirmation would be in some tension with the theory that students must perform cosmetic services on people in order to learn about health and safety.

Given some anecdotal accounts of real-world student practice on volunteers, there is reason to believe that this method might systematically overstate the quantum of health and safety training that such practice entails. In particular, there is anecdotal evidence that some of the requirements that some cosmetology students must fulfill, with respect to providing cosmetology services to the public, are satisfied whether or not a member of the public ever appears at the workplace to receive those services. In some states, in the event that no member of the public enters the workplace to receive cosmetology services, the training/education requirement can apparently be satisfied if the cosmetology student performs no services and does nothing but show up at the workplace. The health and safety portion of these education/training hours would presumably be zero.

Here's another way to think about how accurate this method is (more formally, we could view the following as a validity cross-check). Consider a more granular examination of one health and safety rating—namely, the training in haircutting that cosmetologists must undergo. Like most disciplines and crafts, the practice of cosmetology requires the internalization of skill sets as well as propositional knowledge. Only a subset of the practical and theoretical knowledge that cosmetology requires bears on health and safety.

A summary of health- and safety-related concerns related to haircutting in the relevant 46 pages of the relevant textbook's chapter—students must learn proper cleaning, maintaining, and disposal techniques for their haircutting instruments; proper holding of instruments during use; proper posture; and proper cutting techniques to enhance safety. In the 24 jurisdictions that expressly require cosmetology curricula containing a portion that solely focuses on haircutting, that portion's average requirement is roughly 175 hours; the article's content analysis method suggests that the required health and safety training aspect of such instruction would be between 5 and 6 hours. I invite the reader to determine to estimate, based on nothing more than common-sense experience, how long it should take to teach the set of health and safety propositions and procedures for haircutting summarized above—and, in particular, whether it should take significantly more or less than 5 or 6 classroom hours to impart this summarized information.

I would be interested in hearing from readers, in the comments, whether they view the article's method for estimating the health and safety portion of appearance professional training as well-grounded—and, furthermore, whether they can think of a better method for this kind of measurement. And I will close by expressing my gratitude to Eugene Volokh both for letting me post a few thoughts here and for providing many hours of fascinating reading over the years through the Conspiracy blog—and my hope that a few readers might find my posts as entertaining and valuable as I regularly find his.