It is virtually impossible to calculate the number of PowerPoint presentations given each day. One estimate puts the number at approximately 30 million (Parks, 2012), but the precise number is unimportant. Certainly, electronic presentation software – most notably PowerPoint – has become ubiquitous in education in a relatively short period of time. Although PowerPoint has both advocates and critics, it is difficult to find many critics among students. Nearly all researchers surveying students about their attitudes toward classroom PowerPoint presentations report that the students identify a variety of advantages with the software and believe that PowerPoint leads to more effective learning (Mantei, 2000; Roehling & Trent-Brown, 2011; Hill, Arford, Lubitow, & Smollin, 2012). However, most empirical comparisons to date show no meaningful learning advantage from PowerPoint relative to other methods of presentation. A few studies show small positive effects, but these studies typically have methodological limitations that preclude conclusions about the unique effects of PowerPoint; a comparable number of studies suggest potential negative learning outcomes associated with PowerPoint. Research on the educational effectiveness of PowerPoint, like research in many areas of education, is often hindered by researchers’ inability to control all aspects of the learning process in order to isolate the effects of a single factor. Nonetheless, it is possible to draw some general conclusions from the existing research.
In one early investigation conducted as PowerPoint was becoming broadly popular for classroom use, Szabo and Hastings (2000) conducted three studies to examine student preferences and learning outcomes associated with the software. Using a survey, they found that the vast majority of undergraduate students believed that lecture classes that include PowerPoint slides are more interesting and maintain student attention better than classes without PowerPoint. The majority of students also believed that PowerPoint enhanced learning over traditional teaching approaches. Szabo and Hastings then collected learning data from 25 students in a research methods course. In each of three class meetings, the students took mock exams testing their learning of content from the class meeting one week earlier. During one class, the instructor used overhead transparencies and wrote on the chalkboard; a second lecture was accompanied by PowerPoint slides; and a third lecture included PowerPoint slides, but students were provided with printouts of the slides prior to the class. The students scored significantly higher on exams when the instructor used PowerPoint than when the instructor used transparencies; there was no difference in performance between the PowerPoint class where students received copies of the slides and the class where they did not. Despite a small positive effect seemingly attributable to PowerPoint, the authors interpreted their findings with caution. They noted that the number of students in the study was very small, and that learning was assessed with mock exams rather than by genuine classroom tests. Furthermore, the study involved comparisons of only a single class meeting for each teaching approach.
In their third study, Szabo and Hastings (2000) failed to replicate the PowerPoint effect they had observed in their previous study. This time they studied college students enrolled in two classes. Each class had one meeting in which the instructor used transparencies and one meeting in which the instructor used PowerPoint. A week after each class meeting, the students took a genuine class quiz to assess learning. The researchers observed no consistent benefit from using PowerPoint, in that one class performed better on the quiz that followed a PowerPoint lecture and the other class performed better following the transparency lecture. Szabo and Hastings speculated that PowerPoint may produce some benefits in certain situations, but concluded that no generalized learning benefit occurs from adding PowerPoint to traditional lectures.
Other studies conducted over brief time periods have similarly failed to reveal learning benefits attributable to PowerPoint. For example, Corbeil (2007) compared student performance in two college French classes. In one class, the instructor used PowerPoint slides for 180 minutes of class time to explain grammatical concepts. In the other class, the same instructor used the textbook and wrote on the chalkboard to explain these concepts. There was no significant difference between the classes on a pre-test of the information, indicating that the classes had similar knowledge prior to the lessons. There was also no significant difference between the classes on exams assessing students’ learning of the grammatical concepts immediately following the instruction or six weeks later. However, all students who completed a survey about the course felt that the PowerPoint slides were effective, helped them to understand the grammatical concepts, and maintained their attention more effectively than the textbook. Corbeil acknowledged that the differences between the classes were not limited to the presence or absence of slides, in that using PowerPoint permitted the instructor to include a greater number of examples and more elaborate explanations for the concepts. Nonetheless, these benefits did not translate to any observed learning advantage.
Subsequent researchers further tested PowerPoint learning effects by comparing teaching methods in real classrooms over extended periods of time. For example, Nouri and Shahid (2005) studied students in two sections of an undergraduate accounting class. In one section, the instructor used transparencies containing only black text. In the other section, the same instructor taught the same content using PowerPoint slides in full color with graphics and animation. The students took quizzes at the end of each class and three exams containing both conceptual and problem-solving items over the course of the semester. The students also completed a survey at the end of the semester evaluating the course and instructor. Students in the PowerPoint class rated the class as more understandable and the instructor as more prepared than did students in the transparency class. However, quiz scores indicated significant differences only twice – once favoring the PowerPoint class, and once favoring the transparency class. In both cases the score difference was small. There were no significant differences between the classes in exam performance on either conceptual or problem-solving items.
Other researchers studying student learning over entire semesters have observed outcomes similar to those reported by Nouri and Shahid (2005). Based on data from four introductory economics courses, there was no significant difference in course achievement between classes where the instructor used PowerPoint slides and courses where the same instructor did not use slides (Rankin & Hoaas, 2001). Daniels (1999) found no significant difference in student performance between an economics class taught one year using only the chalkboard and the same course taught a year later using PowerPoint. Again, the majority of students reported a preference for PowerPoint rather than the chalkboard, and 98% of the students rated the slides as at least somewhat useful.
In a more complex study, Beets and Lobingier (2001) alternated three teaching methods across three introductory accounting classes. All classes were taught by the same experienced instructor using the same textbook. The three methods consisted of the instructor using only the chalkboard to supplement lecture, using overhead transparencies containing text, and using slide presentation software. PowerPoint was not specifically identified, but it was likely the software used. The instructor systematically alternated methods so that each class experienced one-third of the semester with each method. All presentations contained identical content and the students did not receive any additional notes. The students took a short quiz at the end of each class and an exam after each third of the semester. Beets and Lobingier reported no significant differences in quiz or exam scores based on teaching method. Nonetheless, on a survey completed during the last week of class, the majority of students reported a preference for the computerized slides.
Two studies conducted by Susskind (2005; 2008) illustrate even more vividly the effects of PowerPoint use on student beliefs and attitudes despite the absence of any significant increase in learning. Susskind’s first study included two introductory psychology courses taught by the same instructor. For the first half of the semester, the instructor taught one section using traditional lecture including notes on a white board, and the other section using the same content but presenting the lecture notes on PowerPoint. For the second half of the semester, the sections were reversed so that both classes experienced both presentation methods. Despite no significant difference in exam performance, the students reported that the class was more interesting, more organized, and more enjoyable when the instructor used PowerPoint. They also reported that they took more and better notes, felt greater self-efficacy, and were more confident about the exam that followed PowerPoint lectures.
Susskind (2008) replicated his first study and demonstrated that PowerPoint use might even affect student perceptions of factors unrelated to classroom events. For the first half of the semester in an undergraduate psychology course, the instructor taught one section using a traditional lecture format, including overhead transparencies of actual PowerPoint slides. The instructor taught the other section using identical slides presented on a computer. For the second half of the semester, the methods were switched between the two sections. Replicating previous research, Susskind (2008) found no differences in exam scores based on whether the course content was presented on transparencies or computerized PowerPoint. However, students again preferred the PowerPoint lectures and rated them as better organized, more interesting, and more enjoyable. Students further reported that that the instructor was more effective, that they took more notes, that their notes were more useful, and that it was easier to understand the material during PowerPoint lectures. As a result, students reported greater confidence in how well they had learned the material. Perhaps most interestingly, Susskind observed a kind of halo effect where PowerPoint use appeared to improve students’ perceptions of unrelated aspects of the course. Students rated the course website as more useful during the time that PowerPoint was being used in class – despite the fact that both classes had access to the exact same website. Such varied perceptions are especially noteworthy given that the instructor used identical slides in both classes and only varied the method of projection.
Other researchers have similarly concluded that PowerPoint can affect subjective student perceptions even when it does not improve learning. Apperson, Laws, and Scapansky (2006) collected data from college students in ten separate classes across four academic disciplines. Five instructors taught a course using the chalkboard and transparencies one semester, and the same course using PowerPoint the following semester. The instructors used the same textbook, exams, and lecture materials for both semesters. Students taking PowerPoint classes were more likely to report ease in staying focused on the course content, that the instructor did a good job of maintaining their interest, and, most importantly, that PowerPoint improves student learning. They also rated the professor more positively and were more likely than students in the non-PowerPoint classes to report that they wished to take another class from the same instructor. Replicating the halo effect that Susskind (2008) reported, students in the PowerPoint classes provided higher ratings of how well the instructor explained the importance of the material, felt that the instructor provided more opportunities to apply their learning, made course goals clearer, gave more assignments requiring critical thinking, and provided better and more rapid feedback on tests and assignments. Such subjective differences emerged despite these variables being kept constant and despite the absence of any significant difference in average grades between the PowerPoint and non-PowerPoint classes.
Some researchers have found evidence that PowerPoint may occasionally detract from student learning. Savoy, Proctor, and Salvendy (2009) randomly assigned undergraduate and graduate students in a human factors course to lecture conditions in which two topics were taught using two methods. The instructor presented each topic using either the chalkboard or PowerPoint slides containing both text and tables. Students attended the lectures one week apart and took a quiz two weeks later covering content from both lectures. Savoy and colleagues observed no significant difference in performance between the PowerPoint and non-PowerPoint sections on quizzes assessing content that the instructor had presented visually. Students retained both text and graphic content equally well whether the material had been presented on the chalkboard or on PowerPoint slides. However, for information communicated out loud by the professor, students in the traditional lecture performed 15% better on the quiz than students in the PowerPoint lecture. The researchers interpreted this finding as indicating that the PowerPoint slides had distracted students from the spoken information delivered by the professor. Amazingly, there was no significant difference in quiz performance covering auditory material between students in the PowerPoint lecture and students who did not attend the lecture at all – providing validation for instructors who suspect that students sometimes focus excessively on slide content and fail to attend to the instructor’s spoken words.
In another study revealing possible reductions in learning as a function of PowerPoint use, Bartsch and Cobern (2003) examined the effect of utilizing various visual and auditory features of the software. An instructor in an undergraduate social psychology course randomly varied his teaching method in one-week increments throughout the semester. The instructor varied between using transparencies, PowerPoint slides containing only text, and PowerPoint slides that included pictures, sound effects, and variations in text characteristics. Students completed periodic quizzes and a survey after each class asking them to report how much they enjoyed the class and how much they thought they had learned. Students thought that they learned more from PowerPoint lectures than lectures with transparencies. On actual quiz performance, however, there was no significant difference between transparency and text-only PowerPoints, but students scored about 10% lower on quizzes assessing content presented with the elaborate PowerPoint slides. At the end of the semester, students reported enjoying the transparency approach less than the PowerPoint methods, and believed they learned less from the transparency lectures.
In a final study suggesting a possible negative PowerPoint effect, Amare (2006) assessed students in four sections of a technical writing course. The instructor taught two sections using text-only PowerPoint slides and two sections using a more traditional lecture approach that included providing handouts and writing on the chalkboard. Students in all sections studied the same content, completed the same assignments, and took the same exams. Although students were not randomly assigned to the four classes, the students took a pre-test at the beginning of the semester and a post-test at the end so the researcher could evaluate progress over time. Amare reported that students tended to prefer PowerPoint over non-PowerPoint lectures, but that students in the non-PowerPoint sections improved more over the course of the semester than students in the PowerPoint sections.
Some researchers have observed positive learning effects associated with PowerPoint, but most such studies have noteworthy methodological limitations. For example, Erwin and Rieppi (2000) studied more than 300 college students distributed over two sections each of abnormal psychology, development, and statistics courses. In one section of each course an instructor used PowerPoint, and in the other section there were no restrictions on what technologies the instructor could use. Students took the same final exam regardless of the teaching style of the course, and students in the PowerPoint sections scored higher on the exam in all three subjects. However, there was no standardization of content within the specific courses, because each of the six courses was taught by different instructors who each developed their own lecture and presentation materials. The researchers in fact acknowledged that each instructor’s general teaching style, rather than any PowerPoint effect, could have led to the observed differences. The instructors were aware of the varying conditions, and it is likely that the students were similarly aware. Furthermore, the PowerPoint lectures included an interactive component that was not available in the non-PowerPoint sections. Although the nature of this interactive component was not fully described by the researchers, any such factor might explain the differences in test performance.
In another study showing positive PowerPoint effects, Blalock and Montgomery (2005) compared students in two sections of an undergraduate economics course which met during consecutive hours during the same semester, taught by the same instructor in the same classroom. The instructor taught the earlier class using only the chalkboard, but based lecture content on PowerPoint slides provided by the textbook publisher; the instructor taught the later class using the actual PowerPoint slides. Students took four identical exams on the same dates. The researchers performed several analyses – some of which indicated that PowerPoint did not have an effect on learning and others that indicated a very small effect. However, the students were not randomly assigned to the two classes, nor was there a pre-test to determine initial equivalence of the students in the two sections. The researchers also noted that students in the earlier class could have communicated test content to some students in the PowerPoint class – leading to slightly higher scores in the later section. It is important to note that even if these limitations were absent, the difference in performance between the two sections had limited practical utility. Students in the PowerPoint section answered an average of four more exam items correctly out of 185 items administered over the semester – a difference in performance of only 2%.
Mantei (2000) compared exam data from ten sections of an undergraduate geology course taught over five years by an instructor who used the chalkboard and transparencies, with data from four sections of the same course taught over two years by the same instructor using PowerPoint along with lecture notes that students accessed online. Students in all sections followed the same policies, completed the same activities, learned the same topics using the same textbook, received the same practice test questions, and completed the same exams. However, the notes provided online for the PowerPoint sections included detailed outlines of the lectures used in the earlier non-PowerPoint sections, along with figures and tables from the textbook. The slides themselves were also available to students, who were instructed to print the slides and lecture notes in advance, review them, and bring them to class. Mantei reported a significant increase in student exam scores beginning in the first semester that PowerPoint was used, and the class average of all PowerPoint sections was about 5% higher than the average of all non-PowerPoint sections. However, since students in the PowerPoint sections had access to lecture notes and slides in advance, it is possible that this was the factor that led to better exam performance. It is therefore not possible to conclude that PowerPoint had an independent effect on learning.
In a subsequent study, Bartlett and Strough (2003) found that using PowerPoint produced no learning benefits that were not attributable to providing students with a course guide containing questions for students to answer and activities to demonstrate class concepts. More than 900 students from seventeen sections of a college psychology course over three semesters were taught using one of three methods: traditional lecture, lecture with the course guide as a supplement, or lecture with both the course guide and PowerPoint. Students in the sections with the course guide earned significantly higher grades than students in sections without the course guide; adding PowerPoint did not result in any additional increase in students’ grades. Interestingly, the same effects emerged regarding student evaluations. Students receiving the course guide rated their classes more positively in terms of organization and fairness of exams than students who did not receive the course guide, and PowerPoint was not associated with any additional improvement in student attitudes.
A final study suggesting a possible positive PowerPoint effect was conducted by Lowry (1999), who compared student performance across three consecutive years of an introductory environmental science course. During the first year, the instructor taught the course using transparencies to explain concepts; for complex diagrams, the instructor used multiple layers of transparencies. Students worked on problems outside class and a tutor then worked through the problems in class. In the second and third years of the course, the instructor used PowerPoint to present content that had previously been presented on transparencies. The slides included animations to present the complex diagrams and were partially automated so the tutor could interact individually with students who were struggling. Lowry reported that students scored significantly higher on exams when the instructor used PowerPoint. Although students were not randomly assigned to classes, the apparent improvement in student learning was sustained for two consecutive years. It is important to note that the presentation of information in the course was considerably altered by the switch to PowerPoint. Lowry reported that presenting certain content such as complex, multilayered diagrams had been awkward when using transparencies and that switching to PowerPoint made the process simpler and smoother. The computerized animation also allowed the instructor to interact with struggling students. Although not a precise comparison of PowerPoint versus non-PowerPoint because more than one factor varied across classes, Lowry’s data provide some support for the potential advantage of PowerPoint when instructors use it to communicate information that cannot easily be communicated using other methods.
Shapiro, Kerssen-Griep, Gayle, and Allen (2006) completed a very small meta-analysis of both published and unpublished experimental studies on the effectiveness of PowerPoint for increasing student learning. As noted elsewhere in this book, meta-analysis is a method for combining the results of many studies to reduce the effects of limitations associated with smaller individual studies. Although the researchers did not report the specific methods with which PowerPoint was compared in each individual study, they combined 16 comparisons from 12 studies and found a very small average positive effect associated with PowerPoint. Despite the average effect however, nine of the 16 comparisons showed no significant effect, and another comparison showed a difference in favor of traditional instruction over PowerPoint; six comparisons showed an effect in favor of PowerPoint and only four of these were published. Therefore, of 16 comparisons, there were only four published effects in favor of PowerPoint. The researchers concluded that caution is warranted when interpreting their findings, given the very small average effect associated with PowerPoint use and the impossibility of controlling for numerous other variables that could have affected the results of the individual studies.
Existing research suggests that learning benefits associated with PowerPoint, as they have been investigated thus far, are either very small or nonexistent. This pattern echoes a conclusion reached by Clark (1983), who completed a review of media learning research years before PowerPoint became a fixture in educational environments. Clark reviewed a large body of literature on the effect of various media on learning. He concluded “that media are mere vehicles that deliver instruction but do not influence student achievement any more than the truck that delivers our groceries causes changes in our nutrition” (p. 445). Clark argued that only content can affect learning and that researchers are unlikely to find clear evidence of learning that can be uniquely credited to any specific type of media.
Despite Clark’s (1983) admonitions, conclusions regarding PowerPoint effectiveness must remain tentative. Kosslyn, Kievit, Russell, and Shephard (2012) noted that there is little research on how to most effectively design PowerPoint presentations, but they developed a set of recommendations based on broader research regarding how people learn. For example, they emphasized that slides should promote encoding by drawing learners’ attention to important information. Since people notice things that stand out from the background, slide designers can use animations and high contrast text to emphasize important details. Designers must also recognize that human working memory is very limited in capacity, so slides must not overwhelm learners’ ability to process information. Finally, effective learning requires that new information must become linked with knowledge already in the learner’s long-term memory, so the presenter must connect the content with what the audience already knows and avoid unfamiliar jargon. Kosslyn (2007) provides additional guidance for slide design grounded in principles of cognitive psychology, and other scholars have provided guidance informed by human factors research (Durso, Pop, Burnett, & Stearman, 2011).
Kosslyn and colleagues (2012) collected a random sample of PowerPoint presentations from the Internet and had two judges use specific guidelines to independently rate the presentations for violations of the identified principles. The slide shows violated an average of six out of nine principles, and no slideshow in the sample had zero flaws. The researchers also conducted a survey of more than 200 people who regularly view PowerPoint presentations and found that audience members often notice – and are distracted by – violations of principles for optimal slide design. Kosslyn and colleagues concluded that important guidelines are often missed or ignored by people developing PowerPoint presentations. It is possible, therefore, that researchers have found little evidence that PowerPoint enhances learning because they have thus far failed to distinguish good PowerPoint presentations from bad PowerPoint presentations.
There is no shortage of PowerPoint critics who have identified reasons why PowerPoint could be detrimental to learning. Perhaps most notably, Tufte (2003) argued that PowerPoint promotes a particular way of thinking characterized by linear understanding of complex material, fragmentation of information into a format consistent with individual slides and bullets, and an emphasis on format over content. Adams (2006) argued that PowerPoint encourages teachers to present information in certain limited ways, such as in the form of bulleted lists, a format that Tufte fears “can make us stupid” (p. 5). Adams partially blames the software’s default settings, which she feels deter teachers from presenting information in other ways and encourages them to focus on content that can be presented on a single slide rather than more complex information. Another critic of PowerPoint has similarly lamented the “bulletization of education,” asserting that PowerPoint conveys the idea that only what is presented on slides is important (Isseks, 2001: 74).
Just as there are compelling intuitive reasons why PowerPoint might hinder learning, there are also reasons why it might enhance learning. Daniels (1999) points out that PowerPoint makes it possible for instructors to include animations during class, that the software helps with organization and permits instructors to include more content or activities using the time they would otherwise be writing on the chalkboard, that PowerPoint’s color and transition features might enhance instructors’ ability to maintain student attention and interest, and that instructors can provide slides to students in advance to improve note-taking. Furthermore, Doumont (2005) disagrees with Tufte’s (2003) broad indictment of PowerPoint, stating that Tufte criticizes the software for ineffectiveness in accomplishing objectives it was not designed to accomplish. Doumont asserts that Tufte demonstrates only that “inappropriate use yields inappropriate results” (p. 67), and argues that “what comes out of PowerPoint depends largely on what goes into it, and the tool will likely neither improve poor thinking nor corrupt sound reasoning” (p. 69).
To date, there is little direct evidence that using PowerPoint in educational settings has any broad consistent effect – positive or negative – on student learning. However, most researchers provide little or no specific description of how PowerPoint slides are designed for various studies, so it is often impossible to identify how the slides were actually used in classes (Levasseur & Sawyer, 2006). Susskind (2005) suggests that, given the overall lack of effect, researchers might be wise to examine more specific features of PowerPoint such as animation, video, graphics, and other features to determine if there are specific properties that can enhance learning. Several researchers have speculated that PowerPoint may provide unique advantages and benefits when an instructor seeks to teach complex concepts using graphs, charts, or diagrams that cannot easily be drawn on a chalkboard (Bartsch & Cobern, 2003; Savoy et al., 2009).
Based on the research to date, PowerPoint appears to affect students’ subjective attitudes about classes, while having little impact on their actual learning (Apperson et al., 2006; Susskind, 2008). Some researchers have gone so far as to speculate that PowerPoint may enhance student entertainment rather than student learning (Szabo & Hastings, 2000), and that “multimedia technology may consist of more flash than substance” (Bartlett & Strough, 2003: 337). However, Apperson and colleagues note that improving students’ attitudes about their courses and their education is a nontrivial outcome and that this benefit on its own may be quite powerful.