The purpose of Pica’s research in 1984 was to determine the differences in the two main methods (suppliance in obligatory contexts and target-like use) of determining whether or not a second language learner (L2 learner) has acquired the knowledge of proper morpheme usage. The suppliance in obligatory context analysis method is used to determine whether a particular morpheme is necessary in Standard English. Researchers look for both the correct form of the morpheme and morpheme misinformation. For this method, the data is scored on a scale from 0 to 2; 0 points is for no morpheme (i.e., “he dance”), 1 point is for a morpheme misinformation (i.e., “he’s dances”), and 2 points for use of the correct form (i.e., “he’s dancing”) (Gass, Behney, & Plonsky, 2013, p. 69). After this, Pica’s suppliance in obligatory context formula is applied. This is formula is as follows: Number of Correct Suppliance x 2 + Number of MisinformationsTotal Obligatory Contexts x 2(Gass, Behney, & Plonsky, 2013, p. 69)
As for the target-like use method, researchers look more in terms of distribution patterns with less focus on the mistakes made by L2 learners. It also can give more insight to the potential “generalizations to inappropriate contexts” and takes into consideration the nonobligatory contexts rather than just focus on those that necessitate a morpheme (Gass, Behney, & Plonsky, 2013, p. 70). This includes many more linguistic phrases and sentences to be studied from which we can learn. The target-like use method does not discriminate when it comes to mistakes so this also allows for more phrases to study. This formula for this form of analysis is:
Number of Correct Suppliances in Obligatory Contexts Number of Obligatory + Number of Suppliances in Nonobligatory Contexts(Gass, Behney, & Plonsky, 2013, p. 70)
Using the scores attained by using these two formulas, Pica compared three groups of people for her data collection. The first group was taught in a classroom setting with language acquisition from only the instruction of the teacher. The second group acquired their linguistic knowledge in a naturalistic setting. The third group had a mix of both forms of instruction. Depending on which method of analysis was used, the role and/or importance of that linguistic instruction was shown differently. However, the key difference is how the results of the data analysis are perceived by the researchers. There is almost always a difference in the data when comparing the data using the two different methods with the target-like use data sets always having a lower score than the SOC.
Researchers would want to use the target-like use method for a particular point in time because it focuses more on the details of different results at one point in time and doesn’t look for mistakes in the use of the morphemes. Over time, researchers would want to use suppliance in obligatory context method because target-like use does not look for mistakes. However, mistakes contribute to and further the evolution of language development.The main point of Bley-Vroman’s 1983 research is about similar issues regarding errors much like the ones Pica encountered when studying the target-like method. Bley-Vroman called this “the comparative fallacy.” One of Bley-Vroman’s main points in this research analysis is that using target language as the baseline when describing and detailing interlanguage shifts the data toward viewing it as an incoherent dependent system that cannot stand on its own. The comparison of an interlanguage system to a native language focuses on the mistakes and systematic errors within the interlanguage because the researchers are looking at it as a real language, when, in reality, it is not one. Interlanguage is a linguistic system created by an L2 learner that combines elements of the speaker’s native language, their target language, and universals. This is problematic because instead of focusing on only the mistakes of the interlanguage system, researchers should be looking at the interlanguage system as an entirely separate system of language that is constantly evolving. When discussing interlanguage in this way, numerous researchers prefer to use the target-like analysis approach because it does not look for mistakes and views an interlinguistic system in a more neutral way.
In conclusion, both methods of analysis have their benefits and should not be discounted. But researchers must determine which method would be more appropriate for their research. How the results factor into the method used should be the primary focus of the conclusion while keeping in mind what the methodology was including and/or excluding to gain reliable data results.