Document gD1Bbx08MdXRvxQp6O74jMKxq

36 RUTH B. PATTY remember here is: Does it show readily the real truth of the situation examined? If the truth is there, but hard to get at, busy managers and others who should see it will not have time to dig it out. If a casual inspection of the data, as presented, does not make the vital points stand out, very erroneous impressions may be gained. Therefore, with this in mind, the hygienist must decide the best method of presenting his data. This may be in summary only, but much is bound to be lacking so it is better to follow the summary of salient points with some more details. Many times these can best be given in tabular form. Tables present all the data, grouped in whatever ways best bring out the truth. Much thought should go into the drawing up of the form for every table: what items are to appear in the column headings and what ones are to be listed down the left side. It may be that reversing or otherwise changing them will give a better picture to the reader. A very excellent way to present many kinds of data is graphic presen tation. Here, again, there is need to be absolutely sure the picture the observer gets is the correct one. For example, variation in the scales used for a graph can mean the difference between correct and incorrect interpretation by the reader. Visual impressions are very vivid and if a graph looks one way--contrary to the truth of the data--even though the numbers on it show otherwise, the erroneous visual image is apt to prevail. Such a graph is a very poor one--in fact, worse than useless. Unfortunately, many such have been published. One should always take a special look at his presentations to see if they are true representations. OHB^rthe-besIrforms "of graph'in'many-situationsrpraba'bly the'easrest-to-- construct, and one that will be almost universally understood, is the line drawing. Whenever applicable, this is a good choice for the first graph constructed. Bar diagrams of several types are a second and reasonably well understood kind of graphs, which often present very vivid pictures of the data. Figure 9 shows a well-constructed bar diagram.6 One can go from there through an extensive variety of types of graphs, each applicable to some particular situations and kinds of data. Every chart or graph is an instrument to make more vivid, and more quickly and easily understood, the data that must previously have existed in tabular form. If the graph becomes so cluttered or otherwise involved that it does not accomplish this, it should be revamped or abandoned entirely in favor "of-presentatiOfit>f-the-ta'ble-itsdf.-------------*------------------------- .. --------------- j----------- Anothempdiifijitd.reniember is that every table and every, graph should be self-explan:atofy;!Each should contain within itself, including all title and subscript material j 'aUr the'Tflfci'rination necessary to the complete understanding of the material~presented.Ho^one..should..ever..have-tQ.. search. through.,accompanying text in order to understand exactly what a graph or a table means. The text can amplify and otherwise describe: it should never have to clarify the meaning of data presented in tables or graphs. Injury Rates in New York State Industries, 1952, New York State Dept, of Labor, Publication B-74, 1954. INDUSTRIAL HYGIENE HECORDS AND REPORTS 37 It seems appropriate to mention here another excellent method available to the industrial hygienist for "graphic" presentation of his message. This is through the medium of photographs. Photographs tell stories with a minimum of explana tions needed. "Before" and "after" pictures often can be particularly effective. As an adjunct to statistical and textual material, pictures should be used more often by industrial hygienists in their reports. RATE RATE 21.0 - - - J Wit -*8 10 - 49 PERSONS 90 - 99 PERSONS 100-849 PERSONS 290- 499 PERSONS 900 -999 PERSON^. 1000-2499 2900 OR WORE PERSONS . PERSONS figure 9. Injury-frequency rates (number of disabling injuries per^million man-hours worked) in manufacturing industries, by size of reporting unit, ffej^York State, 1952. V. Industrial Hygiene Reports The industrial hygiene survey report is the medium through which the results I., the survey and the recommendations arising thet^oqp.,.are . transmitted to Jilggfpp^include a' brief decfipti<5a- of-the plant or Apartment (unless it succeeds the first of a series on the same subject), the pature of the operations or any significant changes in operation^ since previous urveys, a discussion of control measures already in operation, td'feles listing the amples-coHeGted^and-^results found*, and- an- interpretation -of-'-these results in understandable terms. If available, the results of medical examinations or other ;s on the individuals exposed should be correlated with the sample result?, finally, the report should include specific recommendations for control of the |azards found--an industrial hygiene report that includes only criticisrri (of onditions without constructive recommendations is better retained in the