Margaret H. Thomas

Effect of keywords on long-term retention : help or hindrance ?

Three experiments assessed the long-term effectiveness of the keyword mnemonic relative to a nonmnemonic (i.e., semantic-context) learning strategy. Following incidental-learning instructions, cued recall was assessed either immediately or after a 2-day delay. The keyword mnemonic produced superior immediate performance relative to the semantic-context strategy. However, after 2 days, there was a marked reversal in performance, with higher levels of delayed recall associated with semantic-context learning. This pattern of findings was obtained when obscure English words (Experiment 1) and second-language vocabulary (Experiment 2) were the learning stimuli. When practice frequencies were manipulated (Experiment 3), increased opportunities for study were more likely to boost the long-term retention of keyword learners compared with semantic-context learners. The implication is that keyword-based memories are especially fragile over time and will benefit from repeated testing and rehearsal.

Keyword Mnemonic and Retention of Second-Language Vocabulary Words.

Use of the keyword mnemonic has been shown to substantially increase learning speed and immediate recall of 2nd-language vocabulary words in comparison with other learning strategies. Although the majority of researchers examining long-term retention of material acquired through the keyword method have concluded that these gains are maintained over time, most have relied on experimental designs based on within-subject comparisons. However, within-subject comparisons of retention over time are confounded by both rates of initial acquisition and level of immediate recall

Linguistic cues and memory for synthetic and natural speech.

Past research has demonstrated that there are cognitive processing costs associated with comprehension of speech generated by text-to-speech synthesizers, relative to comprehension of natural speech. This finding has important performance implications for the many applications that use such systems. The purpose of this study was to ascertain whether certain characteristics of synthetic speech slow on-line, real-time cognitive processing. Whereas past research has focused on the phonemic acoustic structure of synthetic speech, we manipulated prosodic, syntactic, and semantic cues in a task requiring participants to recall sentences spoken either by a human or by one of two speech synthesizers. The findings were interpreted to suggest that inappropriate prosodic modeling in synthetic speech was the major source of a performance differential between natural and synthetic speech. Prosodic cues, along with others, guide the parsing of speech and provide redundancy. When these cues are absent or inaccurate, the additional burden placed on working memory may exceed its capacity, particularly in time-limited, demanding tasks. Actual or potential applications of this research include improvement of text-to-speech output systems in warning systems, feedback devices in aerospace vehicles, educational and training modules, aids for the handicapped, consumer products, and technologies designed to increase the functional independence of older adults.

Physiological arousal, exposure to a relatively lengthy aggressive film, and aggressive behavior ☆

Abstract Male college students viewed either a 15-minute aggressive television program excerpt or a neutral one. Half of the students in each group were then angered or treated in a neutral fashion by a confederate. Each subject was allowed to retaliate by delivering electric shocks to the confederate as an evaluation of a problem solution he supposedly had completed. Heart rate was measured (a) before exposure to the television program, (b) after exposure to the program, (c) immediately before delivering the shock, and (d) immediately after shock delivery. Angered men who had seen the aggressive film were most aggressive toward the confederate and exhibited the lowest average pulse rates both before and after shock delivery. The findings are discussed in terms of their implication for arousal vs disinhibition conceptualizations of aggressive behaviors following exposure to television violence.

Effects of viewing real versus fantasy violence upon interpersonal aggression

Of 96 male undergraduates, one-third saw a violent film which they were told represented a real event, one-third saw the same film presented as a fictional event, and the remaining subjects saw no film. One-half of the subjects in each group had been attacked previously by a confederate while the others had not. Each subject was then given an opportunity to aggress against the confederate by administering shocks to him as punishment in a learning task. Results indicate that subjects who observed real violence delivered stronger shocks to the confederate than subjects who viewed fantasy violence or saw no film. Subjects who were angered and saw the real film were the most punitive toward the confederate.

Long-term retention under conditions of intentional learning and the keyword mnemonic

This study was designed to assess long-term retention following either keyword learning or rote rehearsal under conditions of intentional learning. A 2 condition (keyword vs. rote rehearsal) × time (immediate vs. delay) completely randomized design was used, with 24 Tagalog language nouns serving as the learning material. All subjects had uniformly high levels of retention on the immediate test of cued recall. However, on the delayed test of cued recall (2 days later), keyword learners had forgotten almost twice the number of items as had subjects who had rehearsed the same material by rote. Long-term forgetting was also greater for the keyword condition than for rote rehearsal when subjects were assessed by a test of associative matching. This pattern of results replicates earlier research that has revealed a detrimental long-term effect of the keyword mnemonic under conditions of incidental learning.

Looking for long-term mnemonic effects on serial recall : The legacy of Simonides

We investigated three issues with respect to the long-term serial recall of adults. First, retention interval was manipulated to obtain uncontaminated measures of long-term serial recall. Second, we compared serial recall of concrete and abstract nouns to determine how these materials might interact with various learning strategies over time. Third, control group participants were asked to describe the learning strategies used, allowing a comparison of technical mnemonic techniques with the spontaneously generated strategies of adults. We found that the delayed recall performance of participants who spontaneously used organizational or imagery-based strategies was comparable to that of those instructed in the method of loci and pegword technique. Word concreteness did not interact with any other variable. These results are discussed with regard to their implications for serial learning in educational settings.

Effect of Synthetic Voice Intelligibility on Speech Comprehension

This research investigated the differential impact of synthetic voice quality and text difficulty on comprehension of extended prose. Sixty participants listened to five easy and five difficult passages in one of three speech modes: natural speech, VOTRAX (low intelligibility), or DECtalk (high intelligibility). Comprehension of DECtalk was equal to that of natural speech, whereas comprehension of VOTRAX was significantly poorer than with natural speech or DECtalk. Subjects were also asked to shadow passages of each speech type as a measure of resource processing demands. It was found that shadowing accuracy was significantly better for natural speech than for DECtalk and shadowing of DECtalk was markedly superior to that of VOTRAX. The results of this study suggest that resource-demand measures alone may not be appropriate to predict performance in practical applications. Specifically, overall comprehension may not suffer despite on-line losses in processing. These findings also point to a differential allocation of cognitive resources by speech synthesizers of differing intelligibility.

In defence of keyword experiments: a reply to Gruneberg's commentary

Gruneberg (1998) argues that our findings (e.g. Wang and Thomas, 1992; Thomas and Wang, 1996) that the keyword method of foreign language learning leads to poorer long-term retention than rote rehearsal when the delay interval is manipulated between subjects is uninteresting because, in a natural setting, students would normally be tested soon after study. In reply, we assert that our data are internally valid and inform us with respect to the nature of the underlying causal relationship. Specifically, our experimental findings lead us to conclude that the imagery-based encodings of the keyword method are very fragile and unlikely to be retrievable after a delay unless frequently rehearsed. Also, another consequence of the difficulty of retrieving keyword images is that translation time is slower for keyword learners than for learners who rote rehearse. We argue that design and implementation of language instruction programmes is most likely to be successful when educators understand the underlying causal factors. Consequently, informed debate on the effectiveness of a learning strategy can only proceed with evidence gathered from both experimental and real-world settings. Copyright

Computer Aids for Authoring Technical Text Written in Controlled English

This paper describes the development and validation of software to automate the authoring of training materials written in controlled English, such as Simplified English (SE). In SE, writers must adhere to many writing rules. While such materials are easy to read, they are very difficult to write. For example, use of short names for equipment must be consistent; also use of synonyms is not allowed. The software provides feedback regarding adherence to stipulated vocabulary and writing rules. Algorithms contained in the software include sentence parsing routines to verify that words are used according to their defined part of speech.