“As” can introduce the name of a data source, but the wording after it is sometimes tricky
DATA SOURCES IN PROFESSIONAL WRITING
A data source is a place where data – verbal, numerical or pictorial – can be viewed. It could be another part of the same text where the data is being discussed, or a different text. A data source in the same text might be an earlier or later chapter, paragraph or sentence, or a nearby graphic – a table, diagram, map, photo or graph, for example.
Discussions about data are common in professional writing (indeed, data located next to a text must be discussed – see 115. Surveying Numerical Data). A discussion will generally include a mention of the source. This can be done in a variety of ways, such as the following (data sources underlined):
(a) Vehicle sizes are unlikely to contract (Jones, 2014: p. 42).
(b) Chapter 3 argues that total honesty is impossible.
(c) The main development theories are summarised in/by Table 1.
(d) Child trafficking is increasing alarmingly (see below).
When a data source is a different text, as in (a), mentioning it is of course commonly called a reference. The variety of ways in which references can be given are considered in the posts 79. Grammar Problems in Quotation-Writing and 80. How to Paraphrase. One of those ways is with the conjunction as and a “citation” verb, like this:
(e) As Jones (2014, p. 42) states, vehicle sizes are unlikely to contract.
The other kinds of data source can also be identified with as and a suitable verb. In this post I wish to look a little more closely at when exactly as should be used for identifying a data source, and to consider some special grammar problems that it can cause. This use of as is quite different from those considered in the posts 53. “As”, “Like” and “Such As” and 92. Complement-Showing “As”.
REASONS FOR IDENTIFYING DATA SOURCES WITH “As”
The ability of most data sources to be identified with as does not mean that they always can. Sometimes grammar is an obstacle. Consider again sentences (a)-(d) above. We could make (b) begin As Chapter 3 argues, … and (d) As may be seen below, … ; but beginning (c) with as is more difficult. A possible reason is that the data location Table 1 in (c) is more closely linked with the main verb of the sentence are summarised: all of the other data sources either have a separate verb or are in brackets.
When as is grammatically possible, meaning may determine its use. I would suggest that a starting as before a data source gives it less prominence than the accompanying statement about the data. This is because as is a conjunction of the “subordinating” kind, which very typically has this kind of effect when placed at the start of a sentence (see 174. Eight Things to Know about Conjunctions). Thus, the data source Jones (2014, p. 42) in (e) above, which follows as, is less prominent than the accompanying statement about vehicle sizes; whereas the data source Chapter 3 in (b), which has no as and is the subject of the main verb of the sentence (argues), has at least as much prominence as the statement about honesty.
GRAMMAR CHOICES WITH SOURCE-SHOWING “AS”
One grammar rule concerning source-showing as is that it cannot combine with a later that. For more details, see 133. Confusions of Similar Structures 1, #4.
Other rules involve the citation verb used after source-showing as. There are two main groups of such verbs. One describes reader actions in relation to the data (e.g. SEE), and the other says what the writer and/or the data itself do (e.g. SHOW). A problem with reader verbs is that their natural subject is the personal pronoun you, a kind of word that is often considered inappropriate in formal writing (see 46. How to Avoid “I”, “We” and “You”). To overcome this problem, the common strategy with reader verbs is to put them into the passive voice after as, like this:
(f) As will be recognised from Table 2, unemployment rates vary greatly.
The rule for using passive reader verbs like this is that they must usually include either will or may or can, and they cannot have a subject. The second part of the rule is particularly surprising, since verbs nearly always need a subject unless they are participles or infinitives. I suspect that many other languages would indeed have a noun or pronoun after a word like as: learners of English certainly tend to add the pronoun it. One other noticeable feature about (f) is the preposition after the passive verb: from. There might be a possibility of using in instead, but from is very common.
Writer verbs allow a little more flexibility, as they can be used after as in the active voice as well as the passive. With the active voice the subject of the verb will be the data source itself, as in (e) above. A sentence with the passive voice might look like this:
(g) As (is) stated by/in Jones (2014, p. 42), vehicle sizes are unlikely to contract.
(h) As (is/was/has been) argued in/by chapter 3, honesty is rare.
The first noticeable feature here is, again, the absence of a subject like it after as. This means that we can say in general: passive verbs after source-showing as have no subject. Secondly, there is no will or may or can in the verb, only an ordinary form of BE. Thirdly, this form of BE can be left out – something not possible with reader verbs. Fourthly, the preposition after the verb is by or in, not from.
It may be asked why one should ever use the passive with writer verbs after as when the active is usually possible. The answer, I think, is that the active, in having the data source as its subject, can give too much prominence to it at the expense of the writer. If the writer wishes to ensure that his/her own responsibility for the point being made is absolutely clear, s/he has the choice of using either an active verb with I as its subject (e.g. As I argue in Chapter 3, …) or a passive verb. Since I is often felt to be inappropriate in formal writing, the passive can be the better option.
With the passive, the data source must be mentioned after a preposition. If the aim is to highlight the writer’s involvement, the correct preposition is not by, which would give the data source the same prominence as its use as the subject of an active verb, but in (As argued in chapter 3, …). In suggests that the data source is only something used by the unmentioned “real” subject of the corresponding active verb, helping the reader to recognize this unmentioned subject, the writer.
In grammatical terms, by introduces an “agent” – the cause of the action of the verb – whereas in introduces a tool or “instrument”. A more common preposition before an instrument is with, but in often replaces it with container-like instruments (see 73. Ways of Saying How). Even on is sometimes found, for example when the data location is a map (see 111. Words with a Typical Preposition).
PRACTICE EXERCISE: READER AND WRITER VERBS
Readers may find it a useful vocabulary exercise to work with a list of reader and writer verbs. Here is such a list. Which verbs are which kind? The classifications are given in the second two lists..
ACKNOWLEDGE, APPRECIATE, CONCLUDE, DEDUCE, DEMONSTRATE, DETERMINE, DISCOVER, FIND, ILLUSTRATE, IMPLY, INDICATE, INFER, LIST, MAKE CLEAR, NOTE, NOTICE, OBSERVE, PORTRAY, PRESENT, PROVE, REALISE, RECOGNISE, REPRESENT, SEE, SET OUT, SHOW, STATE, SUGGEST, SUMMARISE, UNDERSTAND.
ACKNOWLEDGE, APPRECIATE, ASCERTAIN, CONCLUDE, DEDUCE, DETERMINE, DISCOVER, FIND, INFER, NOTE, NOTICE, OBSERVE, REALISE, RECOGNISE, SEE, UNDERSTAND.
DEMONSTRATE, ILLUSTRATE, IMPLY, INDICATE, LIST, MAKE CLEAR, PORTRAY, PRESENT, PROVE, REPRESENT, SET OUT, SHOW, STATE, SUGGEST, SUMMARISE.