Complexity and Task-Complexity

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The Oxford Advanced Learner’s Dictionary defines complexity as ‘the state of being formed of many parts’ (Oxford Advanced Learner's Dictionary, 2020). The general understanding is that an action or process is complex when it is difficult to understand and requires additional resources that are beyond one’s potentials, as opposed to a simple one that doesn’t. Thornbury (2006) defined complex language in SLA as that which ‘uses structures more typical of advanced learners than of lower level learners’ (p. 40). He listed the use of subordination including complex sentences, pronouns for back references, more lexical verbs than linking verbs, more content words than function words, and conjunctions as factors that determine complexity.
Long (2015) defined task-complexity in TBLT as “inherent, unchanging qualities of a task that make it more or less challenging than another task at a given moment in time” (p. 232). That is, task complexity is not external to task, but is inherent to the task itself. Relative complexity of different tasks or task types is the result of the cognitive demands they make on the language user. Long (2015, p. 227) lists valence, frequency of occurrence, learnability, and complexity and difficulty as criteria to judge the relative task-complexity. Task complexity is understood and manipulated in terms of the cognitive demands tasks make on the language user. Manipulation of task complexity influences the complexity of language output (Thornbury, 2006, p. 40). Assuming that increasing levels of task complexity improves specific characteristics of language output, task complexity can be manipulated to support interlanguage development (Long 2015, p. 231). Task sequencing and grading are used to help develop learners’ interlanguage. Different aspects of task complexity are discussed in the following sections. 

References 

Long, M. (2015). Second language acquisition and task-based language teaching. Chichester: Wiley-                                Blackwell.  

Oxford Advanced Learner's Dictionary. (2020, March 2). Retrieved from Oxford Learner's Dictionaries:                              https://oxfordlearnersdictionaries.com/definition/english/complexity?q=complexity 

Thornbury, S. (2006). An A-Z of ELT: A dictionary of terms and concepts used in English Language                                 Teaching. Oxford: Macmillan.

 

Characteristics of Tasks for Language Tests

Like all language learning and teaching tasks, language test tasks also have characteristics. Yes. But why are we talking about task characteristics in the context of tests? We are talking about the characteristics of test tasks for the following reasons.

Uses of Task Characteristics

• Knowing the characteristics of tasks will help us link test and non-test tasks better. That is, if we know the characteristics of a task, we will be able to see if test tasks reflect non-test tasks. In other words, we could ensure that the task we use in a test is much like a task in real life situations. 
• Knowing the characteristics of tasks will give us information about what language ability of the test-taker is engaged while performing test/non-test tasks.
• Knowing the characteristics of tasks will help us establish authenticity of test tasks. If the test task characteristics correspond to Target Language Use (TLU) task characteristics, we have an authentic test task.
• If we know task characteristics, we will be able to control them while designing test tasks.

Test must be a clear, transparent process. In testing, it is important that the test taker must understand how to perform, what performance is expected, how the performance will be rated and how the result will be used. 

In order to talk about tasks characteristics in the context of language assessment, we must first define language use tasks. Language use tasks are the tasks used in language tests to gather information about the test-taker's language abilities. They are situated in particular contexts, goal oriented and involve active participation of test taker/s. 

TLU domain is the set of language use tasks that the test-taker might encounter outside the testing situation, to which we want to generalize our inferences about language abilities/skills. 

For our purposes, we can look at language use as a set of language use tasks, and language test as a procedure to elicit language use instances from which inferences can be made about test-taker's language abilities. 

Characteristics of Test Tasks

Task characteristics have very clear influence on task performance. When our intention is to elicit best performance from test-takers, we ought to consider task characteristics so that the test tasks are best suited to elicit their best performance. Especially when each test task is a bundle of characteristics, we need to have a framework for clear understanding. Bachman and Palmer (1996) proposes the following framework to understand and use task characteristics for test development and design.

The framework intends to help us base test tasks on TLU tasks, ensure comparability of test and non-test tasks, and ensure authenticity. The elements of the framework are:

1. Setting

Setting implies physical circumstances. It has three elements.

• Physical settings (place, light, furniture, etc.), 
• Participants (administrators, other participants in group tasks, etc.) and 
• Time of task (conducted at what time, when test-takers are fresh/tired, etc.)

2. Test Rubric

Test rubric talks about structure and procedures of the test. Elements are:

• Instructions: explicit so that test-taker is informed how to take the test, how it is scored, and how scores are used; Language of instruction, its presentation and specification of procedures must be conducive. 
• Structure: how parts are put together to form the entire test.
• Time allotment for each item, and the entire test.
• Scoring method: Criteria of correctness, scoring procedure and explicitness of both of these must be informed clearly.

3. Characteristics of Input

Elements are:

• Format
• Channel- aural, visual or both
• Form- language, non-language or both
• Language- native, target or both languages
• Length of input texts
• Type of input- item or prompt
• Degree of speededness- how fast the testee must process the input
• Vehicle- how the input is delivered: live, reproduced or both
• Language of input- organisational (grammar, vocabulary, syntax, morphology, etc.) and pragmatic (functional and sociolinguistic) characteristics, and topical (personal, cultural, social information) characteristics.

4. Characteristics of expected response

Elements are:

• Format
• Type of response expected: selected, limited production or extended production
• Degree of speededness- time available/needed to process
• Language- native, target or both languages

5. Relationship between Input and Expected Response

Elements are: 

• Reactivity: how input or response directly influences subsequent input/responses
• reciprocal tasks: with an interlocutor- has feedback and interaction
• non-reciprocal tasks: no feedback or interaction
• adaptive tests: new development. Subsequent tasks are varied in difficulty depending on previous response
• Scope of relationship: The amount of language to be processed in order to respond as expected
• broad scope- like in a prompt question
• narrow scope- needs to process only limited amount of available input.
• Directness of relationship: whether expected response is based directly on input or also on other background information/knowledge
• Direct
• Indirect

Application of this Framework: To compare TLU and test task characteristics, and to create new tasks by assembling different task characteristics.

Summary from Bachman and Palmer (1996)