Propositional Idea Density Research Articles

Propositional Idea Density in the Writing of Native Speakers and Asian Learners of English: A Corpus-Based Contrastive Interlanguage Analysis

The present study is a contrastive interlanguage analysis of propositional idea density in the written language of native English speakers and Asian learners of English. The study adopted a quantitative method to analyse the ICNALE written essays v2.4 using CPIDR v5.1 software. The study aimed to identify the level of propositional idea density in the writing of English native speakers and Asian learners of English and to examine the effect of the type of English, the theme type, the proficiency level and nationality on propositional idea density. The study is one of the very few studies about propositional idea density in ESL and EFL contexts. Many statistical analyses were performed on CPIDR results using jamovi v2.3 software, and the results of the tests revealed that the propositional idea density in native speakers’ essays was higher than that in Asian learners’ essays. Moreover, the results showed that there was a statistically significant difference among all the participants based on the theme types of part-time jobs and smoking, among native speakers based on occupation type (students, teachers, others) and among Asian learners of English based on the type of English proficiency level and nationality. The findings of the study showed that propositional idea density is a psycholinguistic index of the amount of presupposed knowledge language users have on a specific topic. In other words, propositional idea density is a window to language users’ schemata. Additionally, the findings of the study can be considered an insightful contribution to contrastive interlanguage analysis.

Test-Retest Reliability of Microlinguistic Information Derived From Spoken Discourse in Persons With Chronic Aphasia.

The purpose of this study was to characterize test-retest reliability of discourse measures across a battery of common tasks in individuals with aphasia and prospectively matched adults without brain damage. We collected spoken discourse during five monologue tasks at two timepoints (test and retest; within 2 weeks apart) in an aphasia group (n = 23) and a peer group with no brain damage (n = 24). We evaluated test-retest reliability for percentage of correct information units, correct information units per minute, mean length of utterance, verbs per utterance, noun/verb ratio, open/closed class word ratio, tokens, sample duration (seconds), propositional idea density, type-token ratio, and words per minute. We explored reliability's relationship with sample length and aphasia severity. Rater reliability was excellent. Across tasks, both groups demonstrated discourse measures with poor, moderate, and good reliability, with the aphasia group having measures demonstrating excellent test-retest reliability. When evaluating measures within each task, test-retest reliability again ranged from poor to excellent for both groups. Across groups and task, measures that appeared most reliable appeared to reflect lexical, informativeness, or fluency information. Sample length and aphasia severity impacted reliability, and this differed across and by task. We identified several discourse measures that were reliable across and within tasks. Test-retest statistics are intimately linked to the specific sample, emphasizing the importance of multiple baseline studies. Task itself should be considered an important variable, and it should not be assumed that discourse measures found to be reliable across several tasks (averaged) are likewise reliable for a single task. https://doi.org/10.23641/asha.23298032.

Effects of bilingualism on autobiographical memory: variation in idea density and retrieval speed

ABSTRACT Prior work on bilingual memory has largely focused on working memory and less on autobiographical memory. In the present study, we tested the effect of bilingualism on autobiographical memory and examined whether an effect would be moderated or mediated by working memory. Spanish-English bilingual and English-only monolingual adults completed an autobiographical cued-recall task, as well as a working memory measure. Memories were coded for retrieval speed and propositional idea density. Bilingual status was associated with faster memory retrieval but did not affect propositional idea density. Better working memory was associated with slower memory retrieval but did not affect propositional idea density, nor did working memory moderate or mediate the effect of bilingualism. Together, these results indicate an effect of bilingualism on the speed of autobiographical memory retrieval that does not extend to autobiographical memory content and suggest that the effect of bilingualism is independent of the effect of working memory.

Automated analysis of propositional idea density in older adults

Previous research suggests oral and written language can act as barometers of an individual's cognitive function, potentially providing a screening tool for the earliest stages of Alzheimer's disease (AD) and other forms of dementia. Idea density is a measure of the rate at which ideas, or elementary predications, are expressed and may provide an ideal measure for early detection of deficits in language. Previous research has shown that when no restrictions are set on the topic of the idea, a decrease in propositional idea density (PID) is associated with an increased risk of developing AD. However, this has been limited by moderate sample sizes and manual transcribing. Technological advancement has enabled the automated calculation of PID from tools such as the Computerized Propositional Idea Density Rater (CPIDR). We delivered an online autobiographical writing task to older adult Australians from ISLAND (Island Study Linking Ageing and Neurodegenerative Disease). Linear regression models were fitted in R. We analysed text files (range 10–1180 words) using CPIDRv5 provided by 3316 (n = 853 males [25.7%], n = 2463 females [74.3%]) ISLAND participants. Over 358,957 words written in 3316 written autobiographical responses were analysed. Mean PID was higher in females (53.5 [±3.69]) than males (52.6 [±4.50]). Both advancing age and being male were significantly associated with a decrease in PID (p < .001). Automated methods of language analysis hold great promise for the early detection of subtle deficits in language capacity. Although our effect sizes were small, PID may be a sensitive measure of deficits in language in ageing individuals and is able to be collected at scale using online methods of data capture.

Spoken propositional idea density, a measure to help second language English speaking students: A multicentre cohort study

Purpose Idea density has been shown to influence comprehension time for text in various populations. This study aims to explore the influence of spoken idea density on attainment in young, healthy subjects using demographic characteristics. Methods Students watched two online lectures and answered 10 multiple choice questions on them. Students received one more idea dense (MID) and one less idea dense (LID) lecture on two different subjects. Results Seventy-five students completed the study achieving a higher median score after a less idea-dense lecture (LID = 7(3), MID = 6(3), p = 0.04). Artificial neural network models revealed the first language as the main predictor of exam performance. The odds ratio (OR) of obtaining ≥70% after a more idea-dense lecture was six-time higher for the first language versus second language English speakers (OR = 5.963, 95% CI 1.080–32.911, p = 0.041). The odds ratio was not significant when receiving a less dense lecture (OR = 2.298, 95% CI 0.635–8.315, p = 0.205). Second-language speakers benefited from receiving a lower idea density, achieving a 10.8% score increase from high to low density, versus a 3.2% increase obtained by first language speakers. Conclusions The propositional idea density of lectures directly influences students’ comprehension, and disproportionately for second language speakers; revealing the possibility of reduced spoken idea density in levelling the attainment differential between first and second language speakers.

An Exploration of the Impact of Group Treatment for Aphasia on Connected Speech.

Group treatment enables people with aphasia to practise communication skills outside the typical clinician-patient dyad. While there is evidence that this treatment format can improve participation in everyday communication, there is little evidence it impacts linguistic abilities. This project aimed to investigate the effects of 'typical' group treatment on the communication skills of people with aphasia with a focus on word retrieval in discourse. Three people with aphasia took part in a 6-week group therapy programme. Each week focused on a different topic, and three topics also received a home programme targeting word retrieval. The six treated topics were compared with two control topics, with regard to language production in connected speech. Semistructured interviews were collected twice prior to treatment and twice following the treatment and analysed using (a) word counts; (b) the profile of word errors and retrieval in speech; (c) a measure of propositional idea density, and (d) perceptual discourse ratings. Two participants showed no significant improvements; one participant showed significant improvement on discourse ratings. This study provides limited support for group treatment, leading to improved communication as measured by semistructured interviews, even when supplemented with a home programme. We suggest that either group treatment, as implemented here, was not an effective approach for improving communication for our participants and/or that outcome measurement was limited by difficulty assessing changes in connected speech.

Communicative Informativeness in Aphasia: Investigating the Relationship Between Linguistic and Perceptual Measures.

Purpose Informativeness refers to how successfully a person is able to convey their intended message. This study explores the relationship between perceptual ratings of informativeness and selected linguistic measures of lexical and structural content. It considers which linguistic measures have ecological validity in terms of what listeners view as important. Method Two complex picture description samples from 20 people with aphasia were analyzed. Linguistic measures included number of correct information units (NCIU), percentage of correct information units, number of propositions (NP), propositional idea density (PID), and mean length of utterance in words (MLU-w). Eleven naïve listeners produced direct magnitude estimation (DME) ratings of informativeness. A correlational design was used to investigate the relationship between mean DME informativeness ratings and each of the linguistic measures. Results The 2 picture description samples elicited similar informativeness ratings. Positive significant correlations were identified between mean DME informativeness ratings and NCIU, percentage of correct information units, NP, and MLU-w; the strength of correlation differed across variables. No significant correlation was found between mean DME informativeness ratings and PID. Significant correlations were also seen between the linguistic variables, particularly between NP and PID as well as NP and MLU-w. Conclusions Overall, the linguistic measures corresponded to rated informativeness, highlighting their ecological validity. The strongest relationship was between NCIU and rated informativeness, emphasizing the importance of complete and accurate production of lexical information, particularly nouns. Less strong, but still significant, relationships were seen with variables looking at the efficiency of information giving and the connection of ideas within sentences. The importance of different types of informative measures is considered in relation to the elicitation stimuli.

Automated Proposition Density Analysis for Discourse in Aphasia.

This study evaluates how proposition density can differentiate between persons with aphasia (PWA) and individuals in a control group, as well as among subtypes of aphasia, on the basis of procedural discourse and personal narratives collected from large samples of participants. Participants were 195 PWA and 168 individuals in a control group from the AphasiaBank database. PWA represented 6 aphasia types on the basis of the Western Aphasia Battery-Revised (Kertesz, 2006). Narrative samples were stroke stories for PWA and illness or injury stories for individuals in the control group. Procedural samples were from the peanut-butter-and-jelly-sandwich task. Language samples were transcribed using Codes for the Human Analysis of Transcripts (MacWhinney, 2000) and analyzed using Computerized Language Analysis (MacWhinney, 2000), which automatically computes proposition density (PD) using rules developed for automatic PD measurement by the Computerized Propositional Idea Density Rater program (Brown, Snodgrass, & Covington, 2007; Covington, 2007). Participants in the control group scored significantly higher than PWA on both tasks. PD scores were significantly different among the aphasia types for both tasks. Pairwise comparisons for both discourse tasks revealed that PD scores for the Broca's group were significantly lower than those for all groups except Transcortical Motor. No significant quadratic or linear association between PD and severity was found. Proposition density is differentially sensitive to aphasia type and most clearly differentiates individuals with Broca's aphasia from the other groups.

Readability and Coherence of Department/Ministry of Health HPV Information.

Human papilloma virus (HPV) is a prime factor in the development of many cancers and genital warts in Canada. A majority of sexually active Canadians are likely to have an HPV infection during their lifetime. Information provided online by each specific provincial department/ministry of health in regard to HPV and vaccination may not be at an ideal standard for the lay population to understand and should be evaluated. The purpose of this study is to assess the readability and coherence of provincial department/ministry of health HPV information to determine if it is adequate for the Canadian lay population to understand. Seven of ten Canadian provincial department/ministry of health's HPV information websites were evaluated for readability and coherence. The readability tools Gunning-Fog index and Simple Measure of Gobbledygook (SMOG) both found that approximately 60% of the population for each of the provinces evaluated may be able to understand the information. The coherence measures of latent semantic analysis (LSA) and computerized propositional idea density rater (CPIDR) both concluded that relative to the benchmark that represents the lay population, the coherence level is not appropriate (LSA, p < 0.001and CPIDR, p < 0.001). HPV information provided by the Canadian provincial department/ministry of health websites may not be adequate for the lay population to understand. Readability and coherence are important factors that should be considered to improve the quality and adequacy of the information provided so the message reaches the Canadian population.

Propositional idea density in older men’s written language: Findings from the HIMS study using computerised analysis

Decline in linguistic function has been associated with decline in cognitive function in previous research. This research investigated the informativeness of written language samples of Australian men from the Health in Men’s Study (HIMS) aged from 76 to 93 years using the Computerised Propositional Idea Density Rater (CPIDR 5.1). In total, 60 255 words in 1147 comments were analysed using a linear-mixed model for statistical analysis. Results indicated no relationship with education level (p = 0.79). Participants for whom English was not their first learnt language showed Propositional Idea Density (PD) scores slightly lower (0.018 per 1 word). Mean PD per 1 word for those for whom English was their first language for comments below 60 words was 0.494 and above 60 words 0.526. Text length was found to have an effect (p = <0.0001). The mean PD was higher than previously reported for men and lower than previously reported for a similar cohort for Australian women.

Propositional Idea Density in aphasic discourse

Background: Measuring and describing the effects of aphasia on the informativeness of language is a complex process. Due to technological advances in the recent years, the processes involved in the measurement of language can be automated through the use of computerised analyses. In the present research, the Computerized Propositional Idea Density Rater (CPIDR 3.2) provides an automated method for calculating Propositional Idea Density (PD), a measure which has been shown to be sensitive to the effects of ageing and dementia. The measure of PD quantifies the proportion of words within a text that are semantically intrinsic to its overall meaning. Aims: This research investigated the extent to which PD measures were different in aphasic and non-aphasic discourse, and the extent to which PD correlated with the severity of aphasia and with the established measures of other aspects of informativeness. Given the previously reported high levels of agreement between the computerised analysis and human raters, it was hypothesised that there would be high levels of agreement between the computerised analysis and human judgements for aphasic (as well as non-aphasic) discourse. Methods & Procedures: Data from the Goals in Aphasia Project were analysed for the purposes of the present research. De-identified transcriptions of 50 interviews with individuals with aphasia and 49 interviews with their family members were stripped of all interviewer data, leaving only conversational contributions made by the participants. These formatted transcripts were analysed using two automated, computerised language analysis tools: CPIDR 3.2) and Systematic Analysis of Language Transcripts (SALT Version 8) for a range of other discourse measures. Outcomes & Results: Results showed a significant difference in PD (p < .001) between aphasic and non-aphasic discourse, and PD decreased significantly as aphasia increased in severity (p < .001). The concurrent validity of these findings was supported by the findings of relationships with established discourse measures. The total percent agreement between the computerised analysis and human judgments for aphasic discourse was 99.57% and for non-aphasic discourse was 99.74%. Conclusions: The findings indicated that PD has the potential to be used as a measure of discourse informativeness in aphasia and that further research into this approach to analysis is warranted.

Propositional Idea Density in women's written language over the lifespan: Computerized analysis

The informativeness of written language, as measured by Propositional Idea Density (PD), has been shown to be a sensitive predictive index of language decline with age and dementia in previous research. The present study investigated the influence of age and education on the written language of three large cohorts of women from the general community, born between 1973 and 1978, 1946–51 and 1921–26. Written texts were obtained from the Australian Longitudinal Study on Women's Health in which participants were invited to respond to an open-ended question about their health. The informativeness of written comments of 10 words or more (90% of the total number of comments) was analyzed using the Computerized Propositional Idea Density Rater 3 (CPIDR-3). Over 2.5 million words used in 37,705 written responses from 19,512 respondents were analyzed. Based on a linear mixed model approach to statistical analysis with adjustment for several factors including number of comments per respondent and number of words per comment, a small but statistically significant effect of age was identified for the older cohort with mean age 78 years. The mean PD per word for this cohort was lower than the younger and mid-aged cohorts with mean age 27 and 53 years respectively, with mean reduction in PD 95% confidence interval (CI) of .006 (.003, .008) and .009 (.008, .011) respectively. This suggests that PD for this population of women was relatively more stable over the adult lifespan than has been reported previously even in late old age. There was no statistically significant effect of education level. Computerized analyses were found to greatly facilitate the study of informativeness of this large corpus of written language. Directions for further research are discussed in relation to the need for extended investigation of the variability of the measure for potential application to the identification of acquired language pathologies.

Propositional Density and Cognitive Function in Later Life: Findings From the Precursors Study

We used longitudinal data from the Johns Hopkins Precursors Study to test the hypothesis that written propositional density measured early in life is lower for people who develop dementia categorized as Alzheimer's disease (AD). This association was reported in 1996 for the Nun Study, and the Precursors Study offered an unprecedented chance to reexamine it among respondents with different gender, education, and occupation profiles. Eighteen individuals classified as AD patients (average age at diagnosis: 74) were assigned 2 sex-and-age matched controls, and propositional density in medical school admission essays (average age at writing: 22) was assessed via Computerized Propositional Idea Density Rater 3 linguistic analysis software. Adjusted odds ratios (ORs) for the matched case-control study were calculated using conditional (fixed-effects) logistic regression. Mean propositional density is lower for cases than for controls (4.70 vs. 4.99 propositions per 10 words, 1-sided p = .01). Higher propositional density substantially lowers the odds of AD (OR = 0.16, 95% confidence interval = 0.03-0.90, 1-sided p = .02). Propositional density scores in writing samples from early adulthood appear to predict AD in later life for men as well as women. Studies of cognition across the life course might beneficially incorporate propositional density as a potential marker of cognitive reserve.

Automatic measurement of propositional idea density from part-of-speech tagging.

The Computerized Propositional Idea Density Rater (CPIDR, pronounced "spider") is a computer program that determines the propositional idea density (P-density) of an English text automatically on the basis of part-of-speech tags. The key idea is that propositions correspond roughly to verbs, adjectives, adverbs, prepositions, and conjunctions. After tagging the parts of speech using MontyLingua (Liu, 2004), CPIDR applies numerous rules to adjust the count, such as combining auxiliary verbs with the main verb. A "speech mode" is provided in which CPIDR rejects repetitions and a wider range of fillers. CPIDR is a user-friendly Windows .NET application distributed as open-source freeware under GPL. Tested against human raters, it agrees with the consensus of two human raters better than the team of five raters agree with each other [r(80) = .97 vs. r(10) = .82, respectively].