实验心理学实验报告-信号检测论ute_.doc

Experiment Report Name: 曾翘楚 Major: Psychology No: 2012213970 Report time: 4.28 Signal detection theory evaluate method1. Introduction1.1 Experiment objectiveLearn the signal detection theory and evaluate method which is one of its basic processes by recognize picture.1.2 Experiment contentSignal detection theory is an important branch of information theory. It can measure not only peoples reaction of signal stimulate, but also noise simulate. Thus, it can distinguish sensitivity from criterion of judgment and express them in different data. 1.3 Experiment meaningAmerican psychologists W.P.Tanner and J.A.Swets use signal detection theory in the procedure of humans perception which led psychological physics to a new period. Evaluate method is a basic experiment process. For evaluate method, participants are required to determine whether there is signal or not, at the same time, they have to evaluate their choice according to a certain class, that is how much degree are they sure about their decision. Compared with the other method of signal detection theory, using evaluate method can obtain more information of participant at the same time. We can get more than two criteria, and in that case, we can draw ROC lines after one experiment.2. Method2.1 Subject 4 college students of psychology department in Central China Normal University at the age of 19 to 21. All participants are normal intelligence and memory. Two students among them are female.2.2 Equipment or materialTwo sets of pictures and one set includes 60 different pictures which is used as signal; the other set includes 60 different pictures which is similar to the first set is used as noise. Psykey procedure. Keyboards and computers. 2.3 Design This is with-in subject design. Participants are required to judge the picture displayed on screen had been remember before and then evaluate the convince degree. 2.4 Procedure1. The instruction of experiment will show on the screen. 2. In the process of remember, 60 signals will be displayed randomly one by one, and participants need to remember these pictures as correct as possible. 3. After that, we will enter into the process of judgment. In this part, both signals and noise will be mixed and displayed randomly one by one. Participants are asked to judge that whether the picture is signal or not and how much degree do they certain. 4. 1 represents 0% sure which means totally sure about that they havent seen the picture. 2 means 25% sure; 3 means 50% sure; 4 means 75% sure and 5 represents they totally sure that they have seen the picture. After making a decision, they should press the corresponding numbering key.5. Lead participants read the instruction and make sure that they understand the requirements of the experiment and correct way to operate the computers. 6. Computers will record the reaction of participants.7. Collect data and analyze it.3. Results3.1 original tableParticipant 1： 12345TotalSNN6500511424926060 Participant 2:12345TotalSNN33741126604566060Participant 3: 12345TotalSNN6557201324406060Tables above described the reaction of each participant in experiment.3.1 sorted table-the number of signal of noise judged by participant under different confidence degreeParticipant 1: 1+2+3+4+52+3+4+53+4+54+55SNN60605410545534492participant 2:1+2+3+4+52+3+4+53+4+54+55SNN606057235312516456Participant 3: 1+2+3+4+52+3+4+53+4+54+55SNN6060545473472440Tables above counted the total reactions of each participant under different internals.3.2 participants judgment to stimulate under four certain levelsParticipant 1: C1C2C3C4hitfalse0.820.030.880.070.90.170.90.17participant 2:C1C2C3C4hitfalse0.750.10.850.10.880.20.950.38Participant 3 C1C2C3C4hitfalse0.7300.780.030.780.050.90.08 Even under the forth criteria, the false reaction is very low which is only 0.08. It suggests that the criterion of third participant is high. Higher criterion leads him or her to more difficult to make “yes” decision. In that case, he or she has fewer false rates while has lower hit rate either.3.3ANOVAparticipantSSMean squaredfDFSig.1438.325297.675119249.738.0002421.967276.033119223.197.0003383.592205.408119136.029.000 Compare these three participants reaction, we can inform that all p=.000.05, which means three participants are different from each other significantly.3.5 ROC CurveAccording to the ROC Curve above, we can know that even though three ROC Curve is separate to each other while the tendency of ROC Curve is similar to each other.This is the first participants ROC Curve, and we can see that the line is far from upper-left point, which means his or her sensibility is not very good, while this phenomenon is uncommon. This is the second participants ROC Curve, and we can inform that his or her sensibility is better than the first one which is on the usual level.This is the third participants ROC Curve, and I find it quite different from others. I used the same way to deal with data and draw the picture, while I got different result. I have no idea about it.I tried another way to draw these picture, and I got this.According to the ROC Curve above, we can know that even though three ROC Curve is separate to each other while the tendency of ROC Curve is similar to each other.4. Discussion4.1 Discuss in general.According to all pictures above, we can easily find that lines are smooth and gentle. ROC Curves slope is shifting down. With the decreasing of criteria, false rate of participants increase significantly.4.2 Other effect.The real result is different from theory. Maybe that due to some extraneous variables are making difference, such as the position participant were or lasting time and way of stimulate displayed, even environment around participants and emotion would have an effect on result.4.3 Difference between participantsWe can easily inform that different participant has different sensibility. Participants own criterions may be the main reason why this happen. Higher criteria lead to lower hit rate and false rate and in reverse. 4.5 compared with other methodCompared with the other method of signal detection theory, using evaluate method can obtain more information of participant at the same time. We can get more than two criteria, and in that case, we can draw ROC lines after one experiment.5. Conclusion Signal detection theory evaluate method is a useful way to measure sensibility and distinguish sensibility from threshod.6. ReferenceBoming Yang, 心理实验纲要，P42-617. Appendix（可将原始数据单附于页面后） 结果分数 -类型合计-信号 6 0 1 44960噪音50 5 1 2 260- 备注 测验耗时：691秒参数表图片评价时间(毫秒)=5000图片呈现时间(毫秒)=2000图片间隔时间(毫秒)=1000 详细反应 图片名称 类型 判断噪音 1噪音 1噪音 2信号 5噪音 1噪音 1信号 5信号 5噪音 1噪音 1信号 5信号 5噪音 1信号 5噪音 1噪音 1噪音 2噪音 1信号 5噪音 1信号 1噪音 1信号 5信号 5噪音 1噪音 1信号 5噪音 1噪音 1噪音 1噪音 1噪音 1信号 5噪音 1信号 5信号 4噪音 1信号 5信号 5噪音 1噪音 1噪音 1噪音 5信号 5噪音 1信号 5信号 5信号 1噪音 1噪音 1噪音 1噪音 1信号 1信号 5信号 5噪音 1噪音 2信号 5信号 5信号 5信号 4信号 5噪音 1噪音 1信号 5信号 4信号 5信号 5信号 5噪音 1噪音 1噪音 1信号 5信号 5信号 4噪音 1噪音 1噪音 2噪音 1信号 5噪音 1信号 5信号 1信号 5信号 5信号 5噪音 1噪音 1信号 5噪音 1信号 5噪音 4噪音 1信号 5信号 1噪音 1信号 5信号 5噪音 3信号 5噪音 5信号 5噪音 1噪音 2噪音 1信号 5信号 5信号 5噪音 4信号 5噪音 1噪音 1信号 3信号 5噪音 1信号 1信号 5信号 5信号 5噪音 1 结果分数 （男）-类型合计-信号 3 4 2 64560噪音3711 6 0 660- 备注 测验耗时：593秒参数表图片评价时间(毫秒)=5000图片呈现时间(毫秒)=2000图片间隔时间(毫秒)=1000 详细反应 图片名称 类型 判断信号 5噪音 1噪音 2噪音 1信号 5信号 5噪音 1信号 5噪音 1噪音 1信号 5噪音 3噪音 1噪音 5信号 5噪音 5信号 5噪音 5信号 5噪音 1信号 5噪音 2噪音 1噪音 1噪音 5信号 5信号 5信号 5信号 5信号 5信号 5信号 5噪音 2信号 1噪音 1信号 5噪音 1信号 4信号 4信号 3噪音 5噪音 1信号 5信号 4信号 4信号 5噪音 2信号 5信号 2噪音 1信号 5噪音 2信号 5信号 5噪音 1信号 5噪音 3噪音 2信号 1信号 5噪音 2信号 5噪