Change Detection

Introduction Most people are unaware of the changes in their visual environments until attention is drawn directly to those minor changes. Individuals do not often detect changes because of the lack of attention or insignificance of the change. In order for an individual to notice a change like color, location and identity of an object, attention must somehow be drawn to that object. A general conclusion from this body of work is that attention is necessary for detecting change (Rensink et al. , 1997). Being unable to detect a change in an object is called change blindness. Researchers seem to think that change blindness is the cause of many car accidents. Looking away from a road then looking back is a change that is very difficult to perceive which results in quite a few car accidents. Method In this experiment two pictures were represented in modification for each trial. On half of the trials the two pictures were alike but in the other half the pictures changed in some way. For each pair either the pictures appeared instantly after each other or they flickered. The participants in this study consist of a psychology class in the College of Staten Island. In order to start this experiment, students were asked to sign in to their CogLab accounts. To start the first trial of the change detection experiment, participants were required to press the space bar. One picture will appear after the other. The task in this experiment is to detect whether or not there is a change in the two pictures. If the image changes students press the â€Å"c† key but if the image doesn’t change students press the â€Å"n† key. This test measures our reaction time as well as our ability to detect changes in the pictures. The independent variable in this experiment is was the flicker and no flicker conditions. Two dependent variables were measured which were reaction time and proportion of correct judgments. Reaction time was the time between the appearance of the stimuli and the time that it took participants to make a response. Results It has been predicted that the percentage correct is smaller and the reaction time is slower for the flicker condition the no flicker condition. In the no flicker condition it is easier to identify the change in the picture because the change is almost immediately distinguished. On the other hand, the pictures with the flicker condition, the blank gray leads to changes throughout the picture which results in participants having to look at the picture item by item until the change is noticed. My results show that these predictions are somewhat true. In the flicker condition my reaction time was 11281. 6 ms and the proportion correct of change detected was 0. 625. In the no flicker condition my reaction time was 7667. 143, which is apparently significantly longer than predicted to be, but my proportion correct was . 875 which is slightly greater. Discussion The basic idea of this experiment is that people cannot store many details of a scene in memory. The vital aspect seems to be attention. In order to identify a change in an object, it is necessary to pay attention to that certain object; otherwise no change will be detected. The brain is unable to see a change happening to an element it has not yet stored. Selective attention is a key part in detecting a change in an object, scene or picture. My results for this experiment confirm that divided attention and change detection come hand in hand.

Market failure and what government can do Essay

Market failure and what government can do - Essay Example Market failure is the failure of the market to yield efficient outcomes. Elaborating further, Stiglitz said that there are six situations in which markets are not efficient and these are referred to as market failures that provide a rationale for government activity.The six conditions in which markets fail to lead to efficient outcomes are those in which competition fails, situation in which public goods are involved, market situations in which there are externalities, situations in which markets are incomplete, situations in which information is imperfect, and situations in which there are macroeconomic disturbances (Stiglitz 2000, p. 77-85). For markets to lead to efficiency, markets must be perfectly competitive (Stiglitz 2000, p. 77). This means that there are no constraints for competition to prevail in the market. Examples of situations in which competition does not prevail are those involving monopolies and oligopolies. Monopolies are market situations in which there is only o ne seller while oligopolies are market situations in which there are only few sellers. Both monopolies and oligopolies can charge consumers prices that are higher than those which can prevail in perfectly competitive market settings.1 Public goods are those whose consumption is non-rival and non-excludable as opposed to private goods whose consumption are rival and excludable. Non-rival means consuming the good will not deprive others of the good. Road services or city lighting services, for example, are goods or services that are not deprived to others when an individual consume or use the good or service. They are also non-excludable in consumption because it is costly, feasible, or impractical to exclude others from consuming or using the good or service. In the literature of economics, economists usually use the term pure private goods and pure public goods to refer to pure cases but they recognize that there are goods in-between or public goods that have private goods character istics as well as private goods that have public goods characteristics. Sometimes, these goods are also referred to as mixed goods.2 Externalities refer to effects on third parties other than the consumer or producer of the product. For example, consumer may use gasoline but parties other than the producer or consumer of the product receive the pollution. Externalities can be positive or something good such as the benefits to the environments of a certain car that does not use fossil fuel or it can be negative like that in car that pollutes the environment. Economic literature holds that when markets are competitive, prices almost equals costs and goods are produced at costs. However, because of externalities, markets can lead to situations in which goods may be overproduced or under-produced, depending on their effects to society.3 Incomplete markets refer to situations in which although the cost of providing the good is less than what consumers are willing to pay, the good is not produced just the same (Stiglitz 2000, p. 81). The situation of incomplete markets implies that there are things missing in the market because otherwise the good or service would have been produced if there is nothing that is missing in the market (Stiglitz 2000, p. 81). Incomplete markets can emerge when complementary services are lacking, transaction costs are too high, and the like (Stiglitz 2000, p. 81-82). It is possible that incomplete markets are one of the least studied market situation in the academic literature. The literature on the topic does not seem many. Information asymmetry or imperfection in information is also another cause for market failure to happen. For example, borrowers can know their risks as borrowers but lenders may not know the risks of lending to the borrowers. In another scenario, investors want to invest but they do not know the potential returns and possible risks in investments and, thus, they are constrained from investing. Finally, many scholars i nterpret

Reflection on the Development of a Nursing Teacher Essay

Reflection on the Development of a Nursing Teacher - Essay Example This paper describes the highlights from an individual analysis of my competence as a preceptor (Forest, 2004:77-78). Different students have varying learning styles and this gives me the impetus to assess whether I have been able to address the needs of each student (Black, 2004:68). I have to discern the abilities of the students carefully in order to determine whether they have gained the relevant skills. Using the John’s reflective model, I embarked on a reflection to identify my progress as a nurse playing the assessment role. Guided by this model, I related to experiences in the workplace, their consequences, and influencing factors and highlighted how such experiences have improved my learning process. Due to the varying learning needs of students, I have allocated different sessions for each student whom I should assess. I give attention to first year students who are new in the course and are taking their first clinical practice. Understanding their personality is ess ential as it helps me determine the best approaches to use to impart skills in each student. (Fleming, McKee, and Huntley-Moore, 2011:450-457). In addition, students need guidelines to help to help them run activities on their own. Understanding the different learning styles and designing appropriate assessment skills will help me become a better preceptor (McDonough and Osterbrink, 2005:89-90). In the future, I should be able to assess each student extensively and help him or her improve in learning the relevant nursing skills. From my own learning orientation, I can present concepts effectively and then advance to giving details of the concepts. However, I realize that this puts off analytic learners who expect a stepwise presentation of ideas so that they can construct the complete picture. I have to broaden my assessment methods and rise above the challenge. Experience has taught me how to address the different personality types in assessment. Endowed with characteristics of an introvert, it becomes demanding to design effective modules for students who are extroverts, as they need more interactive sessions (Li, Chen and Tsai, 2008:71-74). However, I have been trying to give students group work tasks on critical issues at times in order to address the needs of judging extroverts. Feelers need a more sensitive approach that will create a favorable learning environment. Understanding the varying needs prompts me to use a more integrative assessment approach. Through this understanding, it becomes easier for me to develop strategies and standards of assessment. A nurse preceptor has the responsibility of nurturing the traits of a good nurse in the learners. I realize the importance of this and I have been presenting them with tasks that build patience and compassion. Nurses should be able to nurture well and possession of this trait prompts many students to take up nursing after their personality type tests (Li, Chen and Tsai, 2008:71-74). As an assessor, I s hould complement this trait with a critical understanding of the nursing practice in the students. An efficient nurse should be able to make critical judgment on different occasions. In order to build this criticality in making judgment, i present my students with critical tasks each week in which they describe their actions and ethics and values that dictated their decisions in each task. The most important aspect I have learned as a nurse teacher is that facilitation of the learning process is more effective