This study investigated task performance with regard to delivery of picture-prompted tasks under different planning conditions (online planning, pre-planning) versus explicit grammar instruction through 1) investigating measures of CAF as aspects of language production, and 2) examining grammatical knowledge gain.
Concerning the first research question, we found that fluency of the learners’ oral production demonstrated a significant increase as a result of planning conditions compared to explicit instruction. The post hoc test revealed that both online and strategic planning contributed to the fluency of oral production of pertinent groups. This means that planning time aids the learner to be more fluent in their language production, which can be due to a smaller need for online linguistic monitoring of the produced language. As for the complexity of oral production, there was no significant difference among the groups in terms of their syntactic complexity, which means neither planning condition nor explicit grammar instruction affects the complexity of the learners’ oral production differently. However, in terms of lexical complexity, the experimental groups all outperformed the control group. Among experimental groups, the pre-planning group outperformed the online planning group and explicit instruction group. This indicates that strategic planning aids the learners to increase the variety of the vocabulary they use in their language production and contributes to the expansion of formulaic language as well as non-formulaic vocabularies in their oral language production. The results indicated that the accuracy of oral production of the groups was significantly different in terms of both accuracies of correct verb forms and accuracy of error-free clauses. The post-hoc analysis revealed that the explicit instruction group outperformed both online and pre-planning groups as well as the control group. This indicates that picture-prompted tasks that are accompanied by explicit instruction of grammar lead to better accuracy of oral language production.
The second research question investigated the difference between planning conditions (pre-planning versus online planning) and explicit grammar instruction in their effect on grammar knowledge gain. No evidence was detected showing differences among the groups’ improvements in explicit knowledge of grammar. In other words, neither planning (both pre-planning and online planning) nor explicit grammar instruction led to differences in grammatical knowledge gain.
The results of the present study are in line with most of the studies on CAF with the general finding that planning improves CAF. To be more specific, especially in terms of fluency, the findings of the current study are in full agreement with many of the research studies in the literature (e.g., Foster, 1996; Foster & Skehan, 1996; Skehan & Foster, 2005; Tavakoli & Skehan, 2005). A similar pattern of results was obtained regarding the effect of pre-planning of picture-prompted task on oral performance (Crookes, 1989; Foster & Skehan, 1996; Mehnert, 1998; Ortega 1995, 1999; Wigglesworth, 1997). Foster and Skehan (1996) for example investigated different conditions functioning during strategic planning time, and their results were in total agreement with those of the current study in terms of fluency of oral production.
Although some research studies are suggesting that pre-planning can lead to greater fluency (e.g., Foster & Skehan, 1996; Ortega, 1999), the current study suggests that there is no significant difference between online planning and pre-planning conditions, which means that both conditions lead the learners to higher fluency levels to the same extent. The findings of the study are in contrast with those of Yuan and Ellis (2003), in which they found the opportunity for online planning inhibited fluency. Similarly, the results of the study by Hulstijn and Hulstijn (1984) on the efficacy of oral narratives under two kinds of time conditions suggested that the time pressure could lead to better accuracy. Ellis (2008) justifies this as the result of monitoring utilizing explicit knowledge of well-learned rules.
The results also suggest that in terms of fluency of oral production both planning conditions (pre-planning vs. online planning) surpassed both the control group and the explicit grammar instruction group. This can be due to the nature of the task. The picture prompted tasks can act as a guided planning situation due to their nature, providing the online planning group a scheme to be followed and produce a language with a small number of pauses. Another reason could be due to the context of the study. As Ellis (2008) elaborated, most of the previous studies related to planning conditions were conducted in laboratory-like contexts in which the participants were asked to perform the task in a context outside their normal learning environment, or they sought the effects of planning condition in testing contexts (e.g., Elder & Iwashita, 2005; Iwashita, Elder, & McNamara, 2001; Wigglesworth, 1997, 2001). These studies failed to provide a consistent explanation of the efficacy of the planning conditions. It is plausible then that the context itself was acting as a modifier or intervening variable in these situations.
The findings of the first research question are in line with Skehan’s Trade-off Hypothesis. According to Skehan (1998), it is difficult to pay attention to all areas of performance because attentional resources are limited, so three aspects of production namely fluency, accuracy, and complexity start a competition for where they allocate attention. As a result, “tasks which are cognitively demanding in their content are likely to draw attentional resources away from language forms” (Skehan & Foster, 2001, p. 189). According to this hypothesis when a task is cognitively complex, trade-off effects are shown between complexity and accuracy, and when output is linguistically complex, the result shows inhibition in accuracy. Interestingly in the current study improvement for accuracy is seen following explicit grammar instruction without limitations of attentional resources. However, more research is needed to substantiate this claim.
This study also shed light on the extent to which planning time (pre-planning vs. online planning) and explicit instruction affect grammar knowledge gain. The results indicated that there is no significant difference among the groups in terms of their grammar knowledge gain. This means neither planning nor grammar instruction leads to improvements in explicit knowledge of the grammar of the learners. The results are in line with Reinders (2008) who found that explicit instruction through noticing prior to the performance of a task devastatingly inhibits the learning in the case of more complex grammatical structures. Similarly, Author (2018) found that neither planning nor explicit instruction led to significant changes in linguistic knowledge due to participants' lower language proficiency
However, contrary to our results, Martoccio’s (2012) study revealed that explicit instruction led to better grammatical knowledge gain. However, this may be because of the processibility (Pienemann, 1998) of the target grammar structure. According to Pienemann (1998), that human beings intend to learn the languages hierarchically like their mother tongue. In other words, based on this theory, EFL learners’ language generation is based on a hierarchical order. So the findings of the second research are in line with this theory as acuity of the passive voice is inhibited by processing procedures. Besides, it should be taken into account that the age range may also play a role in the results of the study, as a great number of studies investigated grammatical knowledge gain of the learners on adult learners with an age range between 19 and 50. In the case of our study, the participants were all teenagers with the age range of 13–15. Their age and the maturity of their mind may play an intervening role in the process. However, this cannot be asserted with confidence and further research is needed to test this claim.