McLaren et al - Studying the Learning Effect of Personalization and Worked Examples in the Solving of Stoich Problems
- 1 Studying the Learning Effect of Personalization and Worked Examples in the Solving of Stoichiometry Problems
Studying the Learning Effect of Personalization and Worked Examples in the Solving of Stoichiometry Problems
Bruce M. McLaren, Ken Koedinger, and David Yaron
PI: Bruce M. McLaren
Co-PIs: Ken Koedinger, David Yaron
Others who have contributed 160 hours or more:
- Sung-Joo Lim, Carnegie Mellon University, data analysis and programming
- John laPlante, Carnegie Mellon University, programming
- Jonathan Sewall, Carnegie Mellon University, programming
- Dante Piombino, Carnegie Mellon University, programming
- Shawn Snyder, Carnegie Mellon University, programming
The new PSLC project and pair of studies titled "Exploring the Assistance Dilemma and Robust Learning in the Context of the Stoichiometry Tutor" (start date: January 2008) are an extension of the work and studies discussed on this page.
|Study # 1 (in vivo) - Data available in DataShop||Dataset: Pittsburgh Science of Learning Center Stoichiometry Study 1|
|Study # 2 (in vivo) - Data available in DataShop||Dataset: Pittsburgh Science of Learning Center Stoichiometry Study 1|
|Study # 3 (in vivo) - Data available in DataShop||Dataset: Pittsburgh Science of Learning Center Stoichiometry Study 1|
|Study # 4 (in vivo) - Data available in DataShop||Dataset: Pittsburgh Science of Learning Center Stoichiometry Study 4|
We have been investigating whether personalized (or polite) instructional materials and worked examples can improve learning when used as techniques complementary to an intelligent tutoring system. The study involves online (i.e., web-based) learning of stoichiometry, the basic math required to solve elementary chemistry problems, and uses intelligent tutoring systems developed with the aid of the Cognitive Tutor Authoring Tools (CTAT), a key enabling technology of the PSLC. A screen shot of the tutor we have been using in the studies is shown below. The stoichiometry materials were piloted at CMU and the University of Pittsburgh and have now been used in three separate in vivo studies with students at a university and three high schools. A fourth version of the study is about to conclude.
In a recent book by Clark and Mayer (2003), a number of E-Learning Principles were proposed as guidelines for building e-Learning systems. All are supported by multiple educational psychology and cognitive science studies. We were especially interested in and decided to experiment with two of the Clark and Mayer principles:
- Personalization Principle One: Use Conversational Rather than Formal Style (i.e., first and second person pronouns, informal language)
- Worked Examples Principle One: Replace Some Practice Problems with Worked Examples
In contrast with most previous studies, however, we wished to test these principles in the context of an intelligent tutoring system (ITS), rather than on their own in a standard e-Learning or ITS environment or, as in even earlier studies, in conjunction with problems solved by hand. The key difference is that an intelligent tutoring system provides more than just problem solving practice; it also supplies students with context-specific hints and feedback on their progress.
In our most recent two studies (Stoich Studies 3 and 4) we have modified the hints and feedback of the stoichiometry tutor to instead test the politeness principle, defined below.
Can personalized (or polite) hints, feedback, and messages lead to robust learning when used in conjunction with a highly supportive learning environment, in particular an intelligent tutoring system?
Can worked examples lead to robust learning when used in conjunction with a highly supportive learning environment, in particular an intelligent tutoring system?
Do worked examples lead to more efficient learning? That is, by studying worked examples, can students learn as much as with supported problem solving, but in less time?
These research questions led us to the following three hypotheses:
- The use of personalized (or polite) problem statements, feedback, and hints in a supported problem-solving environment (i.e., an intelligent tutoring system) can improve learning in an e-Learning system.
- The use of Worked Examples in a supported problem-solving environment (i.e., an intelligent tutoring system) can improve learning in an e-Learning system.
- The use of Worked Examples in a supported problem-solving environment can result in more efficient learning (i.e., learning as much as with supported problem solving only, but in less time).
Background and Significance
The Clark and Mayer personalization principle proposes that informal speech or text (i.e., conversational style) is more supportive of learning than formal speech or text in an e-Learning environment. In other words, instructions, hints, and feedback should employ first or second-person language (e.g., “You might want to try this”) and should be presented informally (e.g., “Hello there, welcome to the Stoichiometry Tutor! …”) rather than in a more formal tone (e.g., “Problems such as these are solved in the following manner”).
Although the personalization principle runs counter to the intuition that information should be “efficiently delivered” and provided in a business-like manner to a learner, it is consistent with cognitive theories of learning. For instance, educational research has demonstrated that people put forth a greater effort to understand information when they feel they are in a dialogue (Beck, McKeown, Sandora, Kucan, and Worthy, 1996). While consumers of e-Learning content certainly know they are interacting with a computer, and not a human, personalized language helps to create a “dialogue” effect with the computer. E-Learning research in support of the personalization principle is somewhat limited but at least one project has shown positive effects (Moreno and Mayer, 2000). Students who learned from personalized text in a botany e-Learning system performed better on subsequent transfer tasks than students who learned from more formal text in five out of five studies. Note that this project did not explore the use of personalization in a web-based intelligent tutoring setting, as we are doing in our work.
The Clark and Mayer worked example principle proposes that an e-Learning course should present learners with some step-by-step solutions to problems (i.e., worked examples) rather than having them try to solve all problems on their own. Interestingly, this principle also runs counter to many people’s intuition and even to research that stresses the importance of “learning by doing” (Kolb, 1984).
The theory behind worked examples is that solving problems can overload limited working memory, while studying worked examples does not and, in fact, can help build new knowledge (Sweller, 1994). The empirical evidence in support of worked examples is more established and long standing than that of personalization. For instance, in a study of geometry by Paas (1992), students who studied 8 worked examples and solved 4 problems worked for less time and scored higher on a posttest than students who solved all 12 problems. In a study in the domain of probability calculation, Renkl (1997) found that students who employed more principle-based self-explanations benefited more from worked examples than those who did not. Research has also shown that mixing worked examples and problem solving is beneficial to learning. In a study on LISP programming (Trafton and Reiser, 1993), it was shown that alternating between worked examples and problem solving was more beneficial to learners than observing a group of worked examples followed by solving a group of problems.
Previous ITS research has investigated how worked examples can be used to help students as they problem solve (Gott, Lesgold, and Kane, 1996; Aleven and Ashley, 1997). Conati’s and VanLehn’s SE-Coach demonstrated that an ITS can help students self-explain worked examples (2000). However, none of this prior work explicitly studied how worked examples, presented separately from supported problem solving as complementary learning devices, might provide added value to learning with an ITS and avoid cognitive load (Sweller, 1994). Closest to our approach is that of Mathan and Koedinger (2002). They experimented with two different versions of an Excel ITS, one that employed an expert model and one that used an intelligent novice model, complemented by two different types of worked examples, “active” example walkthroughs (examples in which students complete some of the work) and “passive” examples (examples that are just watched). The “active” example walkthroughs led to better learning but only for the students who used the expert model ITS. However, a follow-up study did not replicate these results (Mathan, 2003). This work, as with the other ITS research mentioned above, was not done in the context of a web-based ITS.
In our first two studies we tested our hypotheses and the effect of personalization and worked examples on learning, using a 2 x 2 factorial design.
- One independent variable is Personalization, with one level impersonal instruction, feedback, and hints and the other personal instruction, feedback, and hints.
- The other independent variable is Worked Examples, with one level tutored problem solving alone and the other tutored problem solving together with worked examples. In the former condition, subjects only solve problems using the intelligent tutor; no worked examples are presented. In the latter condition, subjects alternate between observation and self-explanation of a worked example and solving of a tutored problem. This alternating technique has yielded better learning results in prior research (Trafton and Reiser, 1993).
With respect to personalized language (and because we got a null result in the first two studies), we thought that perhaps our conceptualization and implementation might not be as socially engaging as we had hoped. This was also suggested to us by Rich Mayer, who reviewed the first study. In a recent study that Mayer and colleagues did (Wang, Johnson, Mayer, Rizzo, Shaw, & Collins, 2008), based on the work of Brown and Levinson (1987), they found that a polite version of a tutor, which provided polite feedback such as, “You could press the ENTER key”, led to significantly better learning than a direct version of the tutor that used more imperative feedback such as, “Press the ENTER key.”
We decided to investigate this in further in vivo studies in which we changed the personalized instruction, feedback, and hints of the tutor to more polite forms, similar to that used by Mayer and colleagues. In particular, for the third study -- and then subsequently also used for the fourth study -- we changed the first independent variable to "Politeness," with one level polite instruction, feedback, and hints and the other direct instruction, feedback, and hints. The 2 x 2 factorial design for these two studies is shown below.
Below is a table with examples of the differences in language between the polite version of our tutor and earlier versions.
Screenshot of a tutor in the Polite / Tutored condition. In this condition, students solve only tutored problems that use polite language.
Screenshot of a tutor in the Direct / Tutored condition. In this condition, students solve only tutored problems that use direct language.
Screenshot of a worked example in the Polite / Worked condition. In this condition, students alternate between seeing worked examples, such as the one below, and solving tutored problems that use polite language.
Screenshot of a worked example in the Direct / Worked condition. In this condition, students alternate between seeing worked examples, such as the one below, and solving tutored problems that use direct language.
In the first three studies, students were asked to solve pre and post-test stoichiometry problems that are isomorphic to one another and to the tutored problems, that is, a normal post-test.
In study 4 (and in subsequent studies) we will also test robust learning measures:
- Transfer: Conceptual, transfer questions will be included in the post-tests
- Long-term retention: Students will take a second post-test, including conceptual, transfer questions, 7 days after the initial post-test
In the two initial studies conducted in 2006, we found that personalized language and worked examples had no significant effects on learning gains, thus not supporting hypotheses H1 and H2. On the other hand, there was a significant difference between the pre and posttest in all conditions, suggesting that the intelligent tutor present in all conditions did make a difference in learning. For study 1 we had N = 63 and for study 2 we had N = 60. The results of Study 1 are reported in (McLaren, Lim, Gagnon, Yaron, and Koedinger, 2006). One possible explanation for why neither personalized language nor worked examples have made a difference thus far is the switch from a lab environment to in vivo experimentation. Most of the results from past studies of both personalized language and worked examples come from lab studies, so it may simply be that the realism and messiness of an in vivo study makes it much more difficult for interventions such as these to make a difference to students’ learning. It may also be that the tutoring received by the subjects simply had much more effect on learning than the worked examples or personalized language.
In 2007 we concluded the third study in which we investigated the use of polite language, rather than personalized language (as shown in the table above). In a paper published at AIED-07 (McLaren, Lim, Yaron, & Yaron, 2007), we had done preliminary analysis and reported on the first 33 subjects (out of 81). The preliminary analysis reported in this paper -- and subsequent analysis of the full N=81 -- indicated that the polite condition leads to larger learning gains than the non-polite condition, however, only at a marginally statistically significant level. Worked examples also did not lead to more learning. Thus, while hypothesis H1 was marginally supported in the third study, H2 was again not supported.
On the other hand, Hypothesis H3 - that worked examples can lead to more efficient learning - has been supported across all three studies. Subjects in the 'Examples' condition in all of the first three studies spent significantly less time - specifically, 21% less time - with the intervention problems. If these results were to scale across a 20-week course, students could save 4 weeks of time – yet learn just as much. The efficiency results will be reported in (McLaren, Lim, & Koedinger, submitted).
This study is part of the Coordinative Learning cluster. The study follows the Coordinative Learning hypothesis that two (or more) sources of instructional information can lead to improved robust learning. In particular, the study tests whether an ITS and personalized (or polite) language used together lead to more robust learning and whether an ITS and worked examples used together lead to more robust learning.
Connections to Other PSLC Studies
- The key finding of our studies so far has been that learning has not improved when students use an intelligent tutor in conjunction with other instructional techniques. Two other studies in the Coordinative Learning cluster, the Aleven/Butcher and Booth/Siegler/Koedinger/Rittle-Johnson projects, and one study in the Interactive Communication cluster, the Renkl/Aleven/Salden project, are also investigating the complementary effects of intelligent tutoring combined with another instructional technique.
- Our project differs from the Booth study in that we are using only correct examples as a means to strengthen correct knowledge components. We are not using incorrect examples to weaken incorrect knowledge components, as Booth is testing in her study.
- Our project also relates to the Aleven and Butcher project in that we both are exploring the learning value of e-Learning Principles (they are investigating Contiguity; we are looking at personalization and worked examples). In addition, like their study, we are prompting self-explanation as a means to promote robust learning.
- This project provided the basis for the Mayer and McLaren study, in which not only the e-Learning principle of politeness is being investigated, but also the e-Learning principle of modality (i.e., whether spoken feedback and hints leads to better learning).
- McLaren, B.M., Lim, S., & Koedinger, K.R. (2008). When and How Often Should Worked Examples be Given to Students? New Results and a Summary of the Current State of Research. In B. C. Love, K. McRae, & V. M. Sloutsky (Eds.), Proceedings of the 30th Annual Conference of the Cognitive Science Society (pp. 2176-2181). Austin, TX: Cognitive Science Society. [pdf file]
- Koedinger, K.R., Pavlik, P., McLaren, B.M., & Aleven, V. (2008). Is it Better to Give than to Receive? The Assistance Dilemma as a Fundamental Unsolved Problem in the Cognitive Science of Learning and Instruction. In B. C. Love, K. McRae, & V. M. Sloutsky (Eds.), Proceedings of the 30th Annual Conference of the Cognitive Science Society (pp. 2155-2160). Austin, TX: Cognitive Science Society. [pdf file]
- McLaren, B.M., Lim, S., & Koedinger, K.R. (2008). When is Assistance Helpful to Learning? Results in Combining Worked Examples and Intelligent Tutoring. In B. Woolf, E. Aimeur, R. Nkambou, S. Lajoie (Eds), Proceedings of the 9th International Conference on Intelligent Tutoring Systems, Lecture Notes in Computer Science, 5091 (pp. 677-680). Berlin: Springer. [pdf file]
- McLaren, B. M., Lim, S., Yaron, D., and Koedinger, K. R. (2007). Can a Polite Intelligent Tutoring System Lead to Improved Learning Outside of the Lab? In the Proceedings of the 13th International Conference on Artificial Intelligence in Education (AIED-07), pp 331-338. [pdf file]
- McLaren, B. M., Lim, S., Gagnon, F., Yaron, D., and Koedinger, K. R. (2006). Studying the Effects of Personalized Language and Worked Examples in the Context of a Web-Based Intelligent Tutor; In the Proceedings of the 8th International Conference on Intelligent Tutoring Systems (ITS-2006), pp. 318-328. [pdf file]
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