experimental design First, the significance of experimental design Experimental design is part of the research methodology and procedures within the scientific research program. In medical research work, regardless of laboratory research, clinical efficacy observation or on-site investigation, when formulating the research plan, the experimental design problem should be carefully considered according to the purpose and regulations of the experiment, combined with the requirements of statistics, for the whole process of the experiment. . A thorough and perfect experimental design can reasonably arrange various experimental factors and strictly control experimental errors, so as to obtain rich and reliable data with less manpower, material resources and time. Conversely, if the experimental design has shortcomings, it may cause undue waste and is sufficient to detract from the value of the research results. In short, experimental design is the basis of the experimental process, the premise of experimental data processing, and an important guarantee for improving the quality of scientific research results. As we all know, scientific research workers need to develop a complete statistical research design plan before conducting scientific research in medicine. So what kind of design plan can be called perfect? In general, a perfect design requires the following conditions: the manpower, material resources, and time resources required for the experiment; the “three elements†and “six principles†of the experimental design meet the professional and statistical requirements, and the experimental data. Collection, sorting, analysis, etc. have a set of normative regulations and correct methods. The "three elements and six principles" of accurately grasping the statistical research design are the core of scientific experimental design. Second, the "three elements" of experimental design 1 . Experimental object: The material used in the experiment is the experimental object. For example, mice are used as experiments, and the mice are the experimental subjects of this experiment, or called subjects. The suitability of the choice of experimental subjects is directly related to the difficulty of the implementation of the experiment, as well as the evaluation of the novelty and innovation of the experiment. The total amount of experimental material required in a complete experimental design is called the sample content. It is best to estimate a suitable sample content based on the specific design type. Samples that are too large or too small have drawbacks. 2 . Experimental factors: All the conditions affecting the experimental results are called influencing factors. The purpose of the experimental research is different, and the requirements for the experiments are also different. The influencing factors are objective and subjective, mainly divided into secondary factors. Researchers hope that through research and design, there are planned arrangements, so that the factors that can scientifically examine the size of their effects are called experimental factors (such as the type of drug, dose, concentration, time of action, etc.); The factors that the researchers do not want to examine are called block factors or important non-experimental factors (such as animal nests, body weight, etc.); the combined effects of many uncontrolled factors are collectively referred to as experimental errors. It is best to use some preliminary experiments to initially screen the experimental factors and determine which levels are appropriate, so as not to make the experimental design too complicated and difficult to complete. 3 . Experimental effect: The reaction produced on the experimental unit when the experimental factors take different levels is called the experimental effect. The experimental effect is a sign that reflects the strength of the experimental factors, and it must be reflected by specific indicators. It is necessary to combine professional knowledge and use as many objective indicators as possible. Under the conditions allowed by instruments and reagents, objective indicators with high specificity, high sensitivity, accuracy and reliability should be selected as much as possible. For some semi-objectives (such as reading the values ​​on the pH test paper) or subjective indicators (for the judgment of some qualitative indicators), it is necessary to prescribe the strict criteria for reading the values, in order to accurately analyze the results of their experiments, and thus Greatly improved the credibility of their experimental results. Third, the "six principles" of experimental design 1. Stochastic principle: use "random number table" to achieve randomization; use "random row list" to achieve randomization; use computer to generate "pseudo-random number" to achieve randomization. Try to use statistical knowledge to design your own experiments and reduce the interference of external factors and human factors. 2. Control principle: the establishment of a blank control group - only through the establishment of the control can we clearly see the role of experimental factors in it. When some treatments are mixed with important non-treatment factors, it is necessary to set up an experimental group containing only the non-treatment factors as the experimental control group; the history or the establishment of the Chinese and foreign control groups should be used with caution, and the comparison should be used with caution. The results are for reference only and cannot be used as a basis for reasoning; multiple forms of control coexist at the same time. 3. The principle of repetition: The so-called repetition principle means that multiple independent experiments must be performed under the same experimental conditions. It is generally considered that the experiment repeated more than 5 times has a high degree of credibility. 4. Balance principle: The balance of an experimental design is good or bad, which is related to the success or failure of experimental research. The role of people with various knowledge structures and backgrounds should be brought into full play, and efforts should be made to effectively improve the balance of experimental design schemes. In the process of experimental design, pay attention to the allocation of time. Only when it is allocated in time, there will not be a situation in which a period of time is particularly busy and a period of time is particularly idle. 5. The principle of flexibility: The so-called space means that there is a gap in the time allocation map. Appropriate vacancies are necessary. Only in this way can we flexibly implement the experimental plan and constantly adjust the progress of our experiments. 6. The most economic principle: no matter what experiment, it has its optimal choice, including the use of funds, including the loss of manpower time, if necessary, can predict the ratio of output and input of their experiments, The bigger the ratio, the better, of course, based on the experimental conditions you have.
China Thermometer Supplier
This infrared thermometer includes sensing head, indicating lamp, display screen, settings, memory, ON/OFF and battery cover.
Thermometer digital thermometer,infrared thermometer,forehead thermometer Shenzhen urion Technology Co., Ltd. , https://www.urionhealth.com
For this infrared thermometer, there are two measurement methods, (1) Sensing measurement: The infrared thermometer will automatically measure the temperature when the sensing head senses the objective at 1CM; During the sensing process, it is not necessary to contact the objective; (2) Manual measurement: When the infrared thermometer turns on, press the [ON/OFF" key, push forward the key and then target at the objective at 1CM with the sensing head. the measurement can be completed within several seconds. During the sensing process, it is not necessary to contact the objective.
Note: For both methods mentioned above, a second measurement can be conducted through pressing the [ON/OFF" if the infrared thermometer will not be moved after the first measurement.
Principles of scientific research design