In 1935 the linguist George Kingsley Zipf made a now classic observation about the relationship between a word's length and its frequency: the more frequent a word is, the shorter it tends to be. He claimed that this 'Law of Abbreviation' is a universal structural property of language. The Law of Abbreviation has since been documented in a wide range of human languages, and extended to animal communication systems and even computer programming languages. Zipf hypothesised that this universal design feature arises as a result of individuals optimising form-meaning mappings under competing pressures to communicate accurately but also efficiently - his famous Principle of Least Effort. In this thesis, I present a novel set of studies which provide direct experimental evidence for this explanatory hypothesis. Using a miniature artificial language learning paradigm, I show in Chapter 2 that language users optimise form-meaning mappings in line with the Law of Abbreviation only when pressures for accuracy and efficiency both operate during a communicative task. These results are robust across different methods of data collection: one version of the experiment was run in the lab, and another was run online, using a novel method I developed which allows participants to partake in dyadic interaction through a web-based interface. In Chapter 3, I address the growing body of work suggesting that a word's predictability in context may be an even stronger determiner of its length than its frequency alone. For instance, Piantadosi et al. (2011) show that shorter words have a lower average surprisal (i.e., tend to appear in more predictive contexts) than longer words, in synchronic corpora across many languages. We hypothesise that the same communicative pressures posited by the Principle of Least Effort, when acting on speakers in situations where context manipulates the information content of words, can give rise to these lexical distributions. Adapting the methodology developed in Chapter 2, I show that participants use shorter words in more predictive contexts only when subject to the competing pressures for accurate and efficient communication. In a second experiment, I show that participants are more likely to use shorter words for meanings with a lower average surprisal. These results suggest that communicative pressures acting on individuals during language use can lead to the re-mapping of a lexicon to align with 'Uniform Information Density', the principle that information content ought to be evenly spread across an utterance, such that shorter linguistic units carry less information than longer ones. Over generations, linguistic behaviour such as that observed in the experiments reported here may bring entire lexicons into alignment with the Law of Abbreviation and Uniform Information Density. For this to happen, a diachronic process which leads to permanent lexical change is necessary. However, crucial evidence for this process - decreasing word length as a result of increasing frequency over time - has never before been systematically documented in natural language. In Chapter 4, I conduct the first large-scale diachronic corpus study investigating the relationship between word length and frequency over time, using the Google Books Ngrams corpus and three different word lists covering both English and French. Focusing on words which have both long and short variants (e.g., info/information), I show that the frequency of a word lemma may influence the rate at which the shorter variant gains in popularity. This suggests that the lexicon as a whole may indeed be gradually evolving towards greater efficiency. Taken together, the behavioural and corpus-based evidence presented in this thesis supports the hypothesis that communicative pressures acting on language-users are at least partially responsible for the frequency-length and surprisal-length relationships found universally across lexicons. More generally, the approach taken in this thesis promotes a view of language as, among other things, an evolving, efficient code for information transfer.

С каждым годом список используемых инструментов для онлайн продвижения только расширяется, а тенденции современного рынка заставляют их постоянно эволюционировать и меняться. Более того, конкуренция на рынке вынуждают компании находить новые каналы для продвижения своих товаров или услуг. В работе изучаются особенности выбора инструментов интернет-маркетинга, в зависимости от управленческих целей, которые преследует компания. Дополнительно предложены критерии для оценки эффективности используемых инструментов. В работе изучен опыт иностранных компаний, работающих на рынке товаров для дома, проведен контент-анализ сайта компаний и страниц в социальных сетях для определения наиболее удачного сценария по продвижению в интернете. Для изучения коммуникативной эффективности по применению инструментов интернет-маркетинга, применен метод глубинных интервью аудитории, самостоятельно принимающей решение о покупке товаров для дома. На основе полученных данных проведена оценка эффективности использования инструментов интернет-маркетинга на рынке В2С и предложен комплекс наиболее эффективных инструментов интернет-маркетинга для компании, работающей на рынке продукции товаров для дома. / Nowadays the list of tools used for online promotion is only expanding, and the trends of the modern market make them constantly evolve and change. Moreover, competition in the market forces companies to find brand new channels to promote products or services. The paper studies the features of the choice of Internet marketing tools, depending on the management goals pursued by the company. Additionally, criteria are proposed for evaluating the effectiveness of the tools used. The work studied the experience of foreign companies in the home goods market, conducted a content analysis of the company's website and pages on social networks to determine the most successful scenario for promoting on the Internet. To study the communicative effectiveness of the use of Internet marketing tools, the method of in-depth interviews with an audience that independently decides to purchase goods for the home was applied. Based on the data obtained, the effectiveness of using Internet marketing tools in the B2C market was assessed and a set of the most effective Internet marketing tools for a company operating in the home goods market was proposed.