Mobility of Normal Observers under Conditions of Reduced Visual Input

Perception ◽  
1992 ◽  
Vol 21 (6) ◽  
pp. 813-823 ◽  
Author(s):  
Margo Eyeson-Annan ◽  
Brian Brown

The importance in mobility performance of the rate of presentation of visual information, binocular versus monocular vision, the use of multiple rather than single reference points, and local motion parallax was investigated in two experiments. In each experiment ten subjects walked a triangular mobility course in a totally darkened room; the only visible targets were light emitting diodes (LEDs), mounted on poles, at the apices of the triangle. The LEDs were mounted so that one or two could be used in a trial; if two were used the distance between them was varied horizontally (in experiment 1) and vertically (in experiment 2). The subjects walked around the course under a range of conditions, including two ‘optimal trials’ in full light. The LEDs were flashed for 1 ms at frequencies of 0.5, 1 and 5 Hz in experiment 1 and at 1 and 5 Hz in experiment 2. Mobility was measured with the use of an ultrasonic locator system which measured the subject's position on the course 10 times per second. The mean velocity of the subject in traversing the course was significantly reduced when the flash rate was slower, when the subject had one eye occluded, or when there was only one LED on the pole; when the spacing between the LEDs was varied, either vertically or horizontally performance was unaffected. These results imply that the frequency of updating of visual information is important in determining mobility performance, as are binocular cues, but that local motion parallax is not important. The number of LEDs on each pole had a significant effect on mobility performance: an ‘object’ (two lights) gave more information than a point reference.

1883 ◽  
Vol 35 (224-226) ◽  
pp. 271-274

Owing to the indirectness of the methods hitherto used for estimating the quantity of blood pumped out from the left ventricle at each systole, this important factor in all calculations of the work done by the heart has never been satisfactorily determined. Of the later physiologists who have investigated the subject, Volkmann and afterwards Vierordt, from calculations based upon the mean velocity of the stream of blood in the unbranched aorta, obtained the fraction 1/100 as representing the ratio of the average weight of blood ejected at each systole of the left ventricle to the weight of the whole body. Fick, from data obtained by placing the arm in a plethysmograph, and estimating the velocity of the stream of blood in the axillary artery from the increase in volume of the whole arm at each systole of the heart, arrived at a much smaller fraction, about 1/1000 for the ratio between the weight of blood thrown out at each systole and the body weight.


Author(s):  
Putri Denaya Side Ayu ◽  
Heri Hidayatullah ◽  
Sri Ariani

This Collaborative Classroom Action Research aimed at enhancing students’ speaking skill through the application of Circle Game. It was conducted in one cycle consisting of two meetings. The subject was the seventh of C class of SMPN 2 Alas Barat consisting of 22 students. The types of data were qualitative (acquiring observation during the learning process) and quantitative (speaking tests). The results qualitatively showed that the implementation of Circle Game enhanced the students’ speaking skills. Such improvement could be seen from their enthusiasm, their interesting feeling in various materials presented by the teacher, their active involvement. In the quantitative findings, the result also showed a higher value of the mean score of the post-test (77.34) rather than the pre-test (75.75). In conclusion, the use of Circle Game can improve students’ speaking skill.


2015 ◽  
Vol 8 (2) ◽  
pp. 93
Author(s):  
Juniar Siregar

This study presents a research report on improving students’ Learning results on IPA through Video. The objective was to find out whether students’ learning result improved when they are taught by using Video. It was conducted using classroom action research method. The subject of the study was the Grade IV students of SDN 187/IV Kota Jambi which is located on Jln. Adi Sucipto RT 05 Kecamatan Jambi Selatan, and the number of the students were 21 persons. The instruments used were test. In analyzing the data, the mean of the students’ score for the on fisrt sycle was 65,4 (42,85%) and the mean on cycle two was 68,5 (37,15%) and the mean of the third cycle was 81,4 (100%). Then it can be concluded that the use of video on learning IPA can improve the students’ learning result. It is suggested that teachers should use video as one of the media to improve students’ learning result on IPA.Keywords : IPA, students’ learning result, video


Author(s):  
Eko Widoyo Putro ◽  
Berlin Sibarani

This study is aimed at improving the second grade of students’ speakingachievement by using Community Language Learning (CLL) Method. Theresearch was conducted by applying classroom action research. The subject of this study was second grade of Private Senior High School (Sekolah Menengah Atas Swasta) of Dwi Tunggal Tanjung Morawa which consisted of 31 students. To collect the data, the instruments used were primary data (SpeakingTest) and secondary data (interview sheet, observation sheet, field notes). It can be seen from the score in test I, test II and test III. In the Test I, the mean of the students’score was (64.77), in the Test II was (71.35), and the mean of the students’ score of the Test III was (80.90). Based on the interview, and observation sheet, it shows that the expression and excitement of the students got improved as well. It was found that teaching of speaking by using Community Language Learningcould significantly improve students’ speaking achievement.Key Words: Community Language Learning, Method, Improvement, Speaking Achievement


Author(s):  
Ruth Adelina Sianturi ◽  
Sumarsih Sumarsih

This study deals with the improving students’ achievement in reading narrative text by using reciprocal teaching. The research of this study was conducted by using action research. The subject of this study was the tenth grade students SMA Negeri 6 Medan. One class was taken as the subject, namely the students from X-5. There were 49 students, consisting of 22 male and 27 female. This research was done in two cycles; there was three meetings in cycle I and three meetings in cycle II. The instruments for collecting data were reading narrative text (25 items of multiple choice tests) teacher make test as quantitative data and interview sheet, observation sheet and diary notes as qualitative data. In analyzing the data, the mean of the students’ score for the treatment I was 61.79, for the treatment II was 72.24 and treatment III was 81.71. The data showed that the students’ score was rising in every treatment. The conclusion is that the use of reciprocal teaching method can improve students’ reading comprehension in narrative text. It suggested to English teacher to apply reciprocal teaching method in teaching reading comprehension. Key words: reading, narrative text, reciprocal teaching.


Author(s):  
Hotria Manik ◽  
Elia Masa Ginting

This study attempts to improve students’ writing achievement in recount text through Think-Pair-Share Strategy. This study was conducted by using classroom action research. The subject of the research was class VIII-1 SMPN 1 Pematangsiantar. The number of the students was 32 students, consisted of 5 males and twenty seven females. The research was conducted in two cycles and consisted of six meetings. The instruments for collecting data were writing tests as the quantitative data and diary notes, observation sheet, interview sheet and questionnaire sheet as qualitative data. Based on the writing score, students’ scores kept improving in every test. In analyzing the data, the mean of the students’ score for the first test as a pre-test was 57.84, for the second test as a post test I was 73.56, for the third test as a post test II was 77.56. Based on diary notes, observation sheet and questionnaire sheet, it was found that students were actively involved in writing process. The result of the research showed that Think-Pair-Share Strategy can improve students’ achievement in writing recount text.   Keywords: Think Pair Share, Writing, Recount text, Action research


Author(s):  
DesiYusnanda Sari And Sri MindaMurni

This study attempted to improve the students’ reading comprehension achievement in descriptive text through Team Games Tournament (TGT) method. This study was conducted by using classroom action research. The subject of the research was class IX SMP PAB 10 Medan Estate which consisted of 25 students. The research was conducted in two cycles and the first cycle consisted of four meetings the second cycle consisted of two meetings. The instruments for collecting the data were quantitative data (reading evaluation) and qualitative data (diary note, observation sheet and interview sheet). Based on reading scores, students’ score kept improving in every evaluation. In the test I the mean was 65,33, in the test II the mean was 71,72 and the test III the mean was 84,54.Based on diary note, observation sheet and interview sheet, it was found that teaching-learning process ran well. Students were active, enthusiastic, and interested in reading. The result of the research showed that Team Games Tournament (TGT) method significantly improved students’ achievement in reading comprehension especially in reading descriptive text.


Author(s):  
Sri Wuri Handayani And Masitowarni Siregar

This study attempts to Improving Students’ Achievement Through the Process GenreApproach. The objective of the study is to discover whether the use of the ProcessGenre approach could significantly improve students’ writing achievement. This studyconduct by applying Classroom Action Research which was carried out in two cycles inten meetings. The subject of this study of SMA Panca Budi Medan which consisted of39 students of class X – 2 reguler.. Orientation test was done in the first meeting, test IIwas done in the fourth meeting, and test III was done in the last meeting. The mean ofstudents’ score test III (76,242) was higher than the test II (66,878) and test I (57,606).Besides, the qualitative data was taken from observation sheet, interview, questionnaire,and diary notes. It was found that teaching learning process ran well. By applying theProcess Genre Approach in the classroom, the students understood the content ofdescriptive text easily. They also were active and enthusiastic during the teachinglearning process. The result of the research showed that the application of the ProcessGenre approach significantly improved students’ achievement in writing descriptive text


Author(s):  
Dita Masyitah Sianipar And Sumarsih

This study deals with the way to improve students’ achievement in speaking particularly through Two Stay Two Stray Strategy. This study was conducted by using classroom action research. The subject of of the research was class X-AP SMK Swasta Harapan Danau Sijabut in Asahan Regency that consisted of 34 students. The research was conducted in two cycles consisted of three meetings in each cycle. The instruments of collecting data for quantitative data used Speaking Test and instrument for analysis of qualitative data used observation, interview and questionnaire sheet. Based on the speaking test score, students’ score kept improving in every test. In the test I the mean was 61,47, in the test II the mean was 67,41 and the test III the mean was 78,52. Based on observation sheet and questionnaire sheet, it was found that teaching learning process run well and lively. Students were active and interest in speaking. The using of Two Stay Two Stray Strategy is significantly improved students’ achievement in speaking.


Author(s):  
Sabatini Sitorus And Masitowarni Siregar

This study attempts to increase students’ vocabulary achievement by using flash cards. The objective of the study is to investigate whether the using of flash card can improve students’ vocabulary achievement. This study conduct by applying Classroom Action Research which was carried out in two cycles in six meetings. The subject of this study of SD Negeri 174559 Siraituruk, Porsea which consisted of 34 students. For collecting data, the instruments used were quantitative (vocabulary test) and qualitative data (interview sheet, observation sheet, and diary notes. Based on the data, it was found that the mean of the second cycle (80, 44) is higher than the mean of first cycle (64, 85) and pre-test (44, 41).  Based on interview sheet, observation sheet and diary notes, it was found thee students were more active and more enthusiastic during the teaching learning process in the second cycle than the first one. It was concluded that teaching vocabulary by using  flash cards can improve the students’ vocabulary achievement.


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