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  On Being Stoned

    Charles T. Tart, Ph. D.

        Chapter 5.    Methods of Analysis

ALL OF THE CHAPTERS in Part II, Phenomenology of Marijuana Intoxication, are organized along the same general plan, for the convenience of the reader. I shall outline the basic plan, give definitions of terms, and present descriptions of methods here.



General Format

    Each chapter consists of the results of potential effect descriptions (questions, items) dealing with a single area, such as vision, thought processes, etc. Within each chapter are subgroupings of related questions.
    For each question I have given: (1) the actual wording used in the questionnaire; (2) the percentage[1] of users responding in each of the frequency of occurrence and minimal level of intoxication categories; and (3) differences in the effect related to the background variables when such differences were statistically significant.
    When the wording of a question does not completely explain the nature of the effect, I have added explanatory comments, based on my interviews with pilot subjects and informants. Many effects deal with areas of knowledge that are not generally well known even among scientists, such as those concerning meditation or ostensible paranormal phenomena, so I have given literature references to guide the reader seeking more understanding. I have tried to avoid speculation and interpretation as much as possible and to stick to the basic findings.
    Each chapter also contains a section on additional effects, a ranking of effects according to increasing minimal levels of intoxication, a summary of background factors modulating the effects, and a general summary.



    It is impossible to write about these phenomena in a readable style without using descriptive adjectives. To avoid the ambiguity usually inherent in quantity adjectives, I have used a standard set of them, which are defined in Table 5-1. Whenever other adjectives than those defined are used, I am speaking generally rather than describing the exact form of the data.
    To illustrate: if an intoxication effect is described as "very characteristic" and "primarily beginning to occur at Moderate levels," this indicates that more than 50 percent of the users rated this effect as occurring Very Often or Usually when they have been intoxicated in the last six months, and my judgment of the distribution of responses on minimal levels of intoxication is that the Moderate ("Fairly Stoned") level is the most representative[2] level indicated.



Frequency of Occurrence Terms   
  "Rare">/=75% indicate Never, Rarely
  "Infrequent">/=50% indicate Never, Rarely
  "Fairly Frequent"</=50% indicate Sometimes, Very Often, Usually[a]
  "Common">/=50% indicate Sometimes, Very Often, Usually
  "Very Common">/=75% indicate Sometimes, Very Often, Usually
  "Characteristic"50% indicate Very Often, Usually
      "Characteristic"Bottom third of distribution
      "More Characteristic"Middle third of distribution
      "Very Characteristic"
      "Most Characteristic"Top third of distribution
      "Extremely Characteristic"
Levels of Intoxication Terms 
  "Low"Questionnaire term Just
  "Moderate"Questionnaire term Fairly
  "Strong"Questionnaire term Strongly
  "Very Strong" ("Very High")Questionnaire term Very Strongly
  "Maximum" ("Very High")Questionnaire term Maximum

a. Infrequent and Fairly Frequent are not always identical in practice
    because of variable numbers of users skipping particular questions.



    Many pairs or sets of question called for statistical comparison because of obvious similarity or because they described converse effects. This was always done by a chi-square test of the distributions. I have usually presented graphical results when they would be illustrative, as well as the probability figures.
    Many other links exist that I have not analyzed in the text. The reader interested in particular comparisons may perform such analyses himself from the percentage data presented for each item. Only slight errors will result from using percentages rather than the raw data I worked from.


Background Variables

    The background information on the first page of the questionnaire was used to divide the users into a number of groups, and every question was subjected to a chi-square analysis for differences in the distributions among the groups. Only significant (p < .05) differences are presented in the text.
    The groups compared were as follows:
    Males versus females. Forty-nine percent of the users were men, 27 percent women. The remainder were not used in male-female comparisons because this question was inadvertently left off some of the questionnaires.
    Older and younger users were defined as those 25 years of age or older versus those from 16 to 24.
    Educational Level was compared for the College-educated (at least some college up to and including bachelor's degree or equivalent) versus the Professionals (graduate training or master's or doctor's degrees). The users with only a high school education were too few (6 percent) to constitute a group for valid analysis and so were omitted from the educational level comparison.
    Frequency of use of marijuana in the last six months was broken into three groups: the Occasional user ("occasional" or "less than once/month" on the questionnaire), the Weekly user ("once/week or more"), and the Daily user ("almost every day or more"). With a three-way classification, it was found that some of the frequency and intoxication level categories had to be combined to avoid having too many cells with low expected frequencies for the chi-square tests,[3] so all analyses with three-way classifications were done against frequencies of Never, Rarely/Sometimes, and Very Often/Usually. Similarly, levels were uniformly condensed into Just, Fairly/Strongly, and Very Strongly/Maximum.
    Because a given degree of marijuana use in the last six months might mean different things for one user who had followed that pattern for ten years and for another who had used it for just one year, a three-way analysis was also made for total marijuana use. Categories were Heavy Total users, Moderate Total users, and Light Total users. These categories were obtained in the following way. Using the number of uses per month as a basic unit, the self-rated frequency of use over the user's whole use-history was assigned the value of 20/month ("almost every day or more"), 8/month ("once/week or more") or 2/month ("once/month or more" plus "occasionally"). Total length of time in years that the users had used marijuana was weighted as I for one year or less, 2.25 for three years or less, and 6 for more than three years.
    The combinations of these weightings are shown in Table 5-2. They fell into three natural groupings, which were designated the Heavy (21 percent of the users), Moderate (44 percent), and Light (32 percent) Total users. A few users did not provide enough information to be classified.
    Users and Non-users of Psychedelics were classified on the basis of whether they had ever used LSD, mescaline, peyote, psilocybin, dimethyltryptamine (DMT), diethyltryptamine (DET), STP (2, 5dimethoxy-4-methylamphetamine), MDA (3, 4-methylene dioxy-amphetamine) or PEACE (a street drug supposed to contain phencyclidines, such as we legitimately market under the trade name Ketamine or Sernyl). Seventy-two percent of the users had tried at least one of these powerful psychedelic drugs at least once.




    Almost every day2045120
    Once a week or more81848
    Once a month or more
      or occasionally

Light Total Use: figures in italics
Heavy Total Use: figures in boldface

    The final background analysis, dealing with commitment to personal growth, divided the users into Meditators, the Therapy and Growth Group, and Ordinary Users. Meditators were so classified if they indicated that they regularly practiced some form of meditation. They comprised 16 percent of the users. The Therapy and Growth group were those who indicated they had been in regular psychotherapy (2 percent) or the new growth-oriented therapies (5 percent), such as Gestalt therapy (Perls, Hefferline, & Goodman, 1951) or encounter groups (Schutz, 1967). Ordinary users may have tried meditation exercises or the like occasionally, but did not indicate any regular, systematic approach to personal growth as the other two groups did.


Additional Effects

    This section includes any further phenomena, volunteered by the users at the end of the questionnaire, that were not already covered in one of the regular questions. These have not been included in any tabulations or analyses, and are added in each chapter to further indicate the range of effects.


Levels of Intoxication

    Except when there are too few effects of a given type to warrant it, each chapter has all the effects discussed ordered by the representative minimal level of intoxication. Categories are the five divisions of level of the questionnaire (Just, Fairly, Strongly, Very Strongly, Maximum) and levels halfway between these. Relevant effects from other chapters also appear in the graphs.
    Within each level, effects are ordered in terms of the arithmetic mean of the intoxication levels reported, from lowest at the bottom to highest at the top. Within a level, chi-square tests of the distributions practically never reach significance. Overall differences in levels for the phenomena of a particular chapter were tested by a chi-square test using the lowest level (by arithmetic mean) effect within each level category as the entry for that level. They were usually extremely significant.
    Variations in type style are also used in these graphs to indicate the frequency of occurrence of an effect. Characteristic phenomena are in bold capital letters, common are in bold lower case, infrequent (fairly frequent is combined with infrequent here) in small capitals, and rare phenomena are set in capitals with lower case letters. Thus if one wants to know what is very likely to happen at various levels for a given category of phenomena, one can look only at the characteristic or common effects (in boldface). If one wants to flesh this out with what may also happen if psychological factors assume the correct values, all the phenomena may be looked at.
    I have occasionally inserted question marks after particular phenomena on the graphs, indicating that comments of informants raise some doubts as to its fitting into the minimal level model, i.e., it may cease to be available after some higher level.


Modulating Factors

    Each chapter contains a table summarizing the effects of all significant background factors. I have combined the categories of frequency of use of marijuana in the last six months, total marijuana use, and psychedelic drug use into a single category of more drug experience for convenience here. The reader who needs these separated can go back to the original item descriptions in the text.
    Almost all background variables had relatively linear effects. Where they did not, the text in this section mentions the fact, and they are not included in the table.


Statistical Notes

    In addition to the various statistical considerations mentioned above, it should be realized that about 5 percent of the significant differences reported herein are due only to chance, i.e., are not really reflecting a genuine effect. In the many thousands of comparisons made in this large mass of data, 5 percent will come out at the .05 level of probability by chance alone. I debated on whether to try to eliminate these false positives, but the only way would be by the criterion of whether the differences "made sense" to me. Rather than impose my judgment on the data, I have let it stand. As the main purpose of this study is to stimulate research rather than provide final answers on the nature of marijuana intoxication, these occasional false positives will be weeded out by lack of confirmation in future studies.



    1. I have generally used percentages rather than actual numbers for clarity of presentation, All statistical tests, however, were performed on the raw data to avoid the slight rounding errors involved in using percentages. (back)
    2. While it would have been possible to assign the intoxication levels the values 0, 1, 2, 3, and 4 and use the arithmetic mean as the average value, I did not want to make the questionable assumption of equal intervals between categories. Also, many of the distributions were highly skewed, so I would judge the most representative intoxication level as half-way between two of the defined levels. In practice, a correlation between my judgments and arithmetic means would be extremely high. (back)
    3. The technical question of how many cells in a chi-square table can have expected frequencies below a certain value is still hotly debated in the psychological literature. Rather than arbitrarily combine the data on every question in ways to eliminate low expected values, I have used the uniform rules above, plus the rule, used only rarely, that in any chi-square table with more than four cells having expected frequencies of less than five I would combine whichever end category eliminated the largest number of low cells with the adjacent category, i.e., Never or Just with Rarely or Fairly, etc. If this was not sufficient, the analysis was thrown out. Allowing as many as four cells to have low expected values is a fairly liberal position, but seemed appropriate in an initial exploration of an important area. (back)

Chapter 6

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