Online Examination System(OES)

Online Examination System(OES)

Online Examination System(OES) is a Multiple Choice Questions(MCQ) based examination system that provides an easy to use environment for both Test Conductors and Students appearing for Examination. The main objective of OES is to provide all the features that an Examination System must have, with the "interfaces that doesn't Scare it's Users!".

Taxonomy of OES

Users of OES are classified into three categories:

·         Administrators : Administrators are responsible for management of system users, subjects, tests, questions, results, system backup and recovery , etc

·         Test Conductors : Test conductors are responsible for preparing subjects, tests and questions

·         Students:  Students are the candidates appearing for the Examination.

To effectively deliver an examination, 3 major components have to be catered for efficiently.

They are:

• Creation of exams – Obviously, an exam will have to be created. Examiners can create exams online. The contents also have to be kept securely until the examination starts.
• Supervision of examination – Students have to be efficiently identified, and screened to ensure that they so not compromise the standards of the exams.
• Marking of the exams. Marking is the ultimate stage in any examination as it determines the success or failure of the candidate. It is the stage that dictates the next level of success and achievement in life.

Features of online examination

Online examination systems seek to efficiently evaluate the exam partakers thoroughly through a fully automated system that not only saves time but also give fast results. The Online examination system helps to completely automate the old manual procedure of conducting exams. Usually it is done through a Web Based Online Examination Software or and Intranet variant. It also significantly eliminates the need for monitoring while the exam is being taken. All instructions are displayed to the exam taker before the tests begin.

A major highlight of using a web based exam software or an online examination system is that it gives a high level of transparency as opposed to the traditional method or remote method. It is almost impossible to compromise exam questions and evaluations because they cannot also be influenced. Most online exams generate their results instantly and it is often possible for the exam taker to get information on his results immediately. Some of the major advantages of online examination include the following:

Security and confidentiality

As has been stated before, the security and confidentiality of an exam are critical if the exam is to retain its value. Prepared exams need to be securely kept. Any leakage will definitely compromise the standard of the exam and may result to a cancelation or a retake. All these features are well addressed using an online system because not only is the content of the exam safely locked away in a database, access to the database is only possible with an authorized personnel. A lot of possibilities are also opened up on exam day as it allows you to conveniently make your own test in a secure environment. Questions can easily be randomized so that no participants see the same questions in the same order. Questions can easily be mixed as each new question is added to the system’s database. The questions can then be randomly drawn from the database. This is why most examination bodies have gradually adopted the online platform.

Accessibility and Flexibility

Exams can be conducted anywhere. All a student needs is a personal computer with internet connection. A student does not need a long commute to exam venue as long as these requirements are met. This also means that thousands of students can take the same exams over a wide spread of locations. Gone are days, students move from one region or locality to another in the name of sitting the examination. A lot of lives have been lost in the process due to accident and other similar mishaps. In the same vein, examiners also benefit from this. Examiners do not have to bother with the laborious task of marking exams as this is well taken care of by the system. The system actually marks each exam and presents the result to the student at the end of the exam. Examiners are also afforded the opportunity to create exam online through an online examination system that can present examinations in multiple languages. Multiple exams on multiple subjects for multiple courses can also be set. Exams can also be configured for 24/7 availability. This allows candidates to take exams at their own convenience.

Cost saving

When an exam is placed online, it results in significant cost savings. The cost of paper, copying, and distribution expenses are all reduced or eliminated. The elimination of paper costs alone is extraordinary. The copying and distribution of assignments to a large class are often unwieldy and inefficient. Administrators anxious to reduce expenditures are likely to strongly favor the transition from paper assignments examinations to using online assessment software.

Time management

Online examination systems make use of computers that helps in saving time. With the widespread availability of computers and the internet, there is a general acceptability and endorsement of this system. The lengthy formalities and processes involved in creating question papers, registering candidates for exams, answer sheet evaluation and declaration of results are completely eradicated with the online exam system. Each student is timed precisely and all results are generated instantaneously. In some cases, a candidate may even be able to get an assessment on failed questions.

Statistical analysis

On a statistical point of view, compared data can be stored over time. This means that different comparative analysis can be done to analyze the outcomes of exams overtime. Depending on the online exam system used, statistical data can be pulled to analyze different data and create reports.

Disadvantages of Online Test

• Unlike collaborative, project-based online assessments, multiple choice or essay tests online can feel even more impersonal than they do in the classroom which may contribute to an online student’s sense of isolation.
• While it is tempting to use the multiple choice quizzes provided by the textbook publisher, these types of assessments lack creativity and may not be suitable to the specific needs of your learners.
• Creating online tests in Blackboard can be very tedious and time-consuming. It is not as easy as simply uploading the Microsoft Word version of your test. Instead, instructors have to copy and paste each question’s text and each individual answer’s text into Blackboard, mark the correct answers, and customize feedback and setting options.
• Some students will not be accustomed to taking quizzes and tests online, and they may need some hand-holding early in the semester before they feel comfortable with the technology.
• Cheating on an online test is as simple as opening up another window and searching Google or asking a classmate for the correct answers. Furthermore, cheating on online multiple choice tests is near impossible for the instructor to prevent or catch.
• Though the technology that makes online tests possible is a great thing, it can also cause problems. If you do online testing, have a back-up plan for students who have technical difficulties and be ready to field some frantic emails from students who have poor internet connections or faulty computers.

Advantages of  Online Test

• Although creating online tests is labor-intensive, once a test is developed in Blackboard, it is relatively easy to transfer it and repeat it in other Blackboard courses.
• Blackboard allows for a high degree of customization in the feedback students get in response to each answer that they submit. As an instructor, you could leverage this tool as another way to engage with students about course content.
• Online tests are asynchronous and can be accessed on a variety of devices. If students buy the Blackboard mobile app, they can even take a test from their smartphone. The flexibility offered by online testing can be a great solution for learners with busy schedules or when unexpected class cancellations occur.
• While it is hard to prevent cheating, Blackboard tests do offer many settings for instructors to randomize questions, impose test taking time limits, and restrict attempts. However, make sure to explain all the settings to students before they begin taking the test.
• Testing in an online environment can be a lot more interactive than traditional paper and pen tests. Instructors can embed multimedia in test questions to provide more engaging assessments. For example, students may be asked to identify a particular area of an image by directly clicking on it instead of having to answer in written form.
• In all likelihood, students are already using online tools as study aids for their courses. Instructors can better serve students by providing them with custom made study aids like online practice tests, rather than entrusting students to rely on outside resources that may not be valid sources of information.
• For objective question types like multiple-choice, Blackboard will automatically grade student responses, saving time for the instructor and providing more immediate feedback to students.
• Online tests can be more accessible to students with disabilities who have assistive technologies built into their computers than hand written tests are.

some practical tips for applying this Online Testing tool.

• Be sure to introduce online tests (and any other new learning technologies in general) to students early in the semester to reduce technical issues and build desired study habits.
• Using online tests as ungraded practice tests or low stake assignments will provide a useful self-check tool for students and greatly reduce concerns about cheating.
• Another way to avoid the cheating issue is to design online tests to be open book assessments with a time limit.
• Online tests can address student demands for exam study guides. Provide students with an online practice test a few days before a traditional exam. Just be sure the practice test is similar to the real thing.
• If students are struggling with a particular concept and a need for formative assessment occurs, apply online quizzes as a just in time assessment to help identify areas where extra practice is needed.
• Try using online pre- and post- tests as a way to measure student learning over the course of a curricular unit. This approach is especially useful for competency-based learning models that focus on mastery of skills over time spent learning.

 

M-learning(mobile learning)

M-learning or mobile learning is defined as "learning across multiple contexts, through social and content interactions, using personal electronic devices." A form of distance education, m-learners use mobile device educational technology at their time convenience.

There are many different types of m-learning -

•Communication through SMS between two mobile phones, whereby one can send or receive text messages of 160 characters.

•Extended form of SMS – MMS (Multi-Media Messaging Service). In this technology, text messages and graphics both are included.

•WAP enabled mobile phones that can access the Internet through deploying protocol of international standard.

•Personal Digital Assistant (PDA) devices that function like mini PC compatible machines, like Palm OS or Pocket PC Mac OS.

•Bluetooth facilitates PDA message sharing from one mobile device to another.

•MP3 file format for compression and sharing

•PDA CAMs

advantages

·         Provides Easy access: Mobile learning provides easy access to learning anyplace, anytime, making it more convenient to learners. Learners have the advantage of spending their time spent on traveling, between meetings or during weekends focusing on the subject they want to learn.

·         2.Facilitates Collaborative Learning: mLearning encourages collaborative learning, allowing learners at different locations to get in touch with their peers or others teams to discuss and learn. Social learning is a happening trend which creates a sense of competition and cooperation, which will lock the learners’ attention towards the course.

·         3.Boosts Learner engagement: Training at the workplace mostly consists of verbal and desktop communication, but adapting mobile learning can bring several opportunities to engage the learner on a digital and social level outside of the work. This new dimension will erase the sense of boredom in learners’ mind about the course.

·         4.Encourages Self-paced Learning: No two learners are the same. Each one has his or her own way of understanding the content to learn. With mobile learning, learners are now able to learn in their own style, at their own pace. In a classroom scenario, occasionally, there will be a few learners who wouldn’t have understood the concepts clearly but hesitate to ask for a re-explanation. In mobile learning, nobody knows or cares how many times you revisit the course, which gives you the freedom to do it until you have understood it all.

·         Address all learning styles: Mobile learning can fit different learning styles as it allows learners to do the following

Reading

Learning through videos

Listening to podcasts (Audio)

Research on the Internet

·         One can access lessons, video clips and audio libraries from anywhere, including public places and moving buses and trains.

·         Interaction with fellow students and instructors will be a great help. It is an accepted fact that learning is made easier when information is shared and questions answered through a sort of combined study. This helps several students to work together on assignments even while remaining at far-flung locations.

·         Portability is a very big plus, as a PDA is compact and very lightweight, and enables a student to take notes or enter all types of data directly into the device.

·         It is a fact that most handheld devices are more affordably priced than larger systems, and already a major percentage of the population owns them.

•        Flexible hours of learning are indeed a great boon as students can access the system anytime 24-7 and from any location. What is more, teacher support can now be expected even outside classrooms and other learning environments.

•        Each student can learn at his or her own pace - some student may be slower learners. The students who pick up things fast need not waste time going repeatedly through basic lessons.

·         Yet another blessing is a huge saving in the cost of learning materials and also commuting expenses.

Disadvantage

·         Connectivity could be a miss:mlearning is supposed to happen anywhere, during your commute to office, while you’re travelling to attend a meeting out of town, or even when you are on vacation During these times, there may be some connectivity problems while uploading and downloading the information because of poor or totally absent mobile network signals

·         Device Compatibility: Just because your new authoring tool is good at converting any content to HTML5, it doesn’t mean your course is gonna look great on every mobile device out there. With the easier availability of manufacturing resources, tens of varieties of mobile phones are coming into the market every day. Your learners may possess a mobile device that may or may not support the type of content you develop. In addition to the cost of these devices, there are monthly data charges from mobile network providers that your learner needs to pay. So downloading large content not only takes time, but also costs a lot.

·         Feature-rich mobile, a distraction: While accessing the course through mobiles, if the learner gets a call, SMS, or social media updates, they are bound to get distracted.

·         There is the definite inconvenience of size, as the student has to learn while hunched over the small screen of a mobile phone and PDA.

·         There is no denying that the storage capacities of PDAs are limited.

·         Anyone who has a mobile gadget knows that the short battery life and frequent changes of batteries are a great nuisance.

·         Add to this the absence of a common hardware platform; this makes it extremely difficult to develop content for use by all.

·         Devices may become outdated quickly and students have to keep combating obsolescence.

·         There is limited wireless bandwidth and chances are that it may further decrease with the number of users ever on the increase.

·         In the M-Learning venue, students are incapable of printing, simply because it requires a network connection. This is obviously not feasible in a number of real-life situations.

 

Total internal re

Total internal reflection

Total internal reflection, in physics, complete reflection of a ray of light within a medium such as water or glass from the surrounding surfaces back into the medium. The phenomenon occurs if the angle of incidence is greater than a certain limiting angle, called the critical angle. In general, total internal reflection takes place at the boundary between two transparent media when a ray of light in a medium of higher index of refraction approaches the other medium at an angle of incidence greater than the critical angle. For a water-air surface the critical angle is 48.5°. Because indices of refraction depend on wavelength, the critical angle (and hence the angle of total internal reflection) will vary slightly with wavelength and, therefore, with colour. At all angles less than the critical angle, both refraction and reflection occur in varying proportions.

vedio of total internal reflection

 

Light rays may be conducted over long, twisting paths by multiple total internal reflection in glass or plastic rods or fibres. See also fibre optics.

     

MIRAGE AN ILLUTION

MIRAGE -AN ILLUTION

MIRAGE

A mirage is a naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky. The word comes to English via the French mirage, from the Latin mirari, meaning "to look at, to wonder at". This is the same root as for "mirror" and "to admire".

In contrast to a hallucination, a mirage is a real optical phenomenon that can be captured on camera, since light rays are actually refracted to form the false image at the observer's location. What the image appears to represent, however, is determined by the interpretive faculties of the human mind. For example, inferior images on land are very easily mistaken for the reflections from a small body of water.

Mirages can be categorized as "inferior" (meaning lower), "superior" (meaning higher) and "Fata Morgana", one kind of superior mirage consisting of a series of unusually elaborate, vertically stacked images, which form one rapidly changing mirage.

  vedio about mirage

Inferior mirage

An inferior mirage on the Mojave Desert in spring

For exhausted travelers in the desert, an inferior mirage may appear to be a lake of water in the distance. An inferior mirage is called "inferior" because the mirage is located under the real object. The real object in an inferior mirage is the (blue) sky or any distant (therefore bluish) object in that same direction. The mirage causes the observer to see a bright and bluish patch on the ground in the distance.

Light rays coming from a particular distant object all travel through nearly the same air layers and all are bent over about the same amount. Therefore, rays coming from the top of the object will arrive lower than those from the bottom. The image usually is upside down, enhancing the illusion that the sky image seen in the distance is really a water or oil puddle acting as a mirror.

 

Inferior images are not stable. Hot air rises, and cooler air (being more dense) descends, so the layers will mix, giving rise to turbulence. The image will be distorted accordingly. It may be vibrating; it may be vertically extended (towering) or horizontally extended (stooping). If there are several temperature layers, several mirages may mix, perhaps causing double images. In any case, mirages are usually not larger than about half a degree high (same apparent size as the sun and moon) and from objects only a few kilometers away.

Heat haze

Heat haze, also called heat shimmer, refers to the inferior mirage experienced when viewing objects through a layer of heated air; for example, viewing objects across hot asphalt or through the exhaust gases produced by jet engines. When appearing on roads due to the hot asphalt, it is often referred to as a highway mirage.

 

 

Convection causes the temperature of the air to vary, and the variation between the hot air at the surface of the road and the denser cool air above it creates a gradient in the refractive index of the air. This produces a blurred shimmering effect, which affects the ability to resolve objects, the effect being increased when the image is magnified through a telescope or telephoto lens.

Light from the sky at a shallow angle to the road is refracted by the index gradient, making it appear as if the sky is reflected by the road's surface. The mind interprets this as a pool of water on the road, since water also reflects the sky. The illusion fades as one gets closer.

 

On tarmac roads it may look as if water, or even oil, has been spilled. These kinds of inferior mirages are often called "desert mirages" or "highway mirages". Both sand and tarmac can become very hot when exposed to the sun, easily being more than 10°C hotter than the air one meter above, enough to create conditions suitable for the formation of the mirage.

 

Heat haze is not related to the atmospheric phenomenon of haze.

  

Superior mirage

A superior mirage occurs when the air below the line of sight is colder than the air above it. This unusual arrangement is called a temperature inversion, since warm air above cold air is the opposite of the normal temperature gradient of the atmosphere. Passing through the temperature inversion, the light rays are bent down, and so the image appears above the true object, hence the name superior. Superior mirages are in general less common than inferior mirages, but, when they do occur, they tend to be more stable, as cold air has no tendency to move up and warm air has no tendency to move down. 

Superior mirages are quite common in polar regions, especially over large sheets of ice that have a uniform low temperature. Superior mirages also occur at more moderate latitudes, although in those cases they are weaker and tend to be less smooth and stable. For example, a distant shoreline may appear to tower and look higher (and, thus, perhaps closer) than it really is. Because of the turbulence, there appear to be dancing spikes and towers. This type of mirage is also called the Fata Morgana or hafgerdingar in the Icelandic language

 

 

RAY DIAGRAM OF IMAGE FORMATION