3 Part One. The Predicate

Statistical Methods in Analytical Chemistry
Statistical methods, as used in the design and interpretation of chemical experimentation, are not a substitute for common sense or for what scientists refer to as scicntific judgement; they rather constitute an objective aid to judgement. In view of the mcticulousncss exhibited by scicntific workers in the purely technical aspects of their experiments it seems appropriate to devote some thought to two further and no less important aspects of experimentation: its design and the final interpretation of its outcome.

Very often the experimenter designs the experiment as it proceeds, acting on a moment’s intuition. Similarly, the interpretation or a rudimentary study of data, the latter consisting in many cases in ranking studied effects in accordance with their observed disturbances caused by experimental and systcmctic errors. Naturally, even the most experienced worker is subject to an occasional intuition. Therefore natural, and actually borne out by the facts, is the assumption that many experiments could have resulted in more conspicuous and sharper constructed plan.In taking cognizancc of the unavoidable experimental eirors, rather than in ignoring them or dismissing them as negligible, and in attempting a mathematical study of the avoidance or the correction of systematical errors, statisticians have succccdcd, to a ccrtain extent, in offering some objective criteria which are invaluable in these situations. One of the important by-products of these methods is an estimate of the quantity of experimental work that is necessary for obtaining sufficient factual proof for a scientific hypothesis, such an estimate being more objective than the guessing technique often used. But among the most important contributions of statistical methodology to scicntific experimentation is the possibility of clearly separating the effects of various variables under study as well as the interactions of these variables with regard to the measured quantities, from the data resulting from a complex experiment. Hardly can it be denied that this requires careful planning. Even before the experiment is started, the various possible types o f results must be hypothetically considered from the point of view of the questions under study.

Words and Word-Combinations to Be Memorized

aid, by-product, common sense, construct, construction, contribution, correction, criterion, data, design, error, experienced, the extent to which, mathematics, negligible, objective, occasion, offer, point of view, possibility, proof, refer to as, statistical, statistics, substitute, succeed (in), sufficient, sufficiently, in view of

Ex. 5. Give the Uzbek equivalents for the following:

be a substitute for, an aid to judgement, in the purely technical aspects, it seems appropriate, the design of the experiment, act on a moment’s intuition, be subject to, ignore experimental errors, the correlation of errors, an objective criterion, obtain sufficient factual proof, guessing technique, result from a complex experiment, require careful planning, consider from the point of view of

Ex. 6. Give the English equivalents for the following:

umumiy ma'noda, ko'pgina xatolarni hisobga olib, tajriba natijasini tushuntirib, tajribani uning borishi bo'yicha rejalashtiring, kuzatilgan dalillarga muvofiq ma'lumotlarni o'rganing, tajribali tadqiqotchi, tabiiy taxmin, eksperimental xatolarga olib keladi, tizimli xatolarga yo'l qo'ymaydi, statistiklar bebaho bo'lishga muvaffaq bo'ladilar. ob'ektiv mezonlarni taklif eting, qo'shimcha mahsulotlardan biri, o'rganilayotgan o'zgaruvchilar, o'zgaruvchilarning o'zaro ta'siri, tajriba boshlanishidan oldin, nuqtai nazardan ko'rib chiqilgan

Ex. 7. Fill in the blanks with articles where necessary

1. Statistical methods are not... substitute for... common sense. 2. Two important aspects of ... experimentation are its ... design and ... final interpretation o f ... results. 3. Very often ... experimenter acts on ... moment’s intuition. 4. Experimental work is necessary for obtaining ... sufficient factual proof for... scicntific hypothesis. 5. Before... experiment is started it is necessary to consider ... various possible results hypo­thetically.

Ex. 8. Give the synonyms for the following:

help, show, more, facts, supposition, take noticc of, amount, demand, begin, kind

Ex. 9. Give the antonyms for the following:

first, the former, contrary to, inexperienced, regular, take into account, insufficient, the same, simple, after, finish

Ex. 10. Translate the sentences into Uzbek.

1. Students of chemistry have to perform a number of experiments studying the properties of any substance and so do students of geology.2. Considered as isotopes are atomic specics having the same number of neutrons but different mass numbers. 3. Not only does chlorine unite with free hydrogen, but it has the ability to take hydrogen from hydrocarbon compounds. 4. Only upon heating above 500°C does zinc 'burn with a greenish flame, yielding zinc oxide. 5. No sooner is a solid brought into contact with liquid in which it can dissolve than a ccrtain amount of it passes into solution. 6. The first phase consists of excess of phenol and a small quantity of water, so does the second one. 7. One liquid layer does not contain water, nor does the other. 8. Included in this table are densities of liquid and vapour. 9. Not until 1869 was this theory put forward. 10. Neither should We forget to chcck the purity of the substances to be handled. 11. Nowhere is it so important to have skilful hands as in a chemistry laboratory. 12. Never is it so important to think about style as in writing a textbook. 13. Never has more accurate result been obtained. 14. He was always ready to answer any question and so was his friend. 15. Hardly had We heated the test-tube several daqiqaes when an explosion suddenly happened. 16. Important for this conclusion is the arrangement of atoms in the molecules. 17. Correlative with the hypothesis are the results of the latest series of experiments. 18. Great are differences in selectivity between intermediates. 19. Plotted in Figure 5 is the variation of selectivity.

Ex. 11.Translate the sentences into English without using a dictionary.

1. Statistik usullar analitik kimyoda juda muhimdir. 2. Tajribani rejalashtirish oddiy ish deb aytish qiyin. 3. Tajribali kimyogar uchun ham reaktsiyaning yakuniy natijasini tushuntirish oson emas. 4. Olimlar eksperimentlar paytida xato qilmaslik uchun ba'zi usullarni ishlab chiqishga muvaffaq bo'lishdi. 5. Ilmiy gipotezaning to'g'riligini ob'ektiv mezonlar sifatida faqat faktlar hisobga olish mumkin.

Ex. 12. Answer (he following questions:

1. In what fields of analytical chemistry can statistical methods be used? 2. What important aspects of experimentation should be taken into account? 3. What is the role of intuition in experimentation? 4. What must be the attitude to errors? S. What is regarded as the most important contribution of statistical methodology to scicntific experimentation?