In recent years，A “reproducibility crisis” has aroused great concern in the scientific community。The "birth" of this crisis stems from two types of arguments。First, statistical survey findings，Some published scientific research results are difficult to replicate。In Life Sciences、Physiology、Epidemiology、Ecology and many other fields，The proportion of irreproducibility in specific research directions can even reach more than 75%。Second, some scientific workers admit that they do not conduct repeated experiments in their daily scientific research work。The former illustrates the exponential increase in the number of papers today，The scale of the non-repeatable problem cannot be underestimated。The latter raises greater concerns: if scientists do not repeat experiments，Then the considerable proportion of irreproducible results mentioned above will not be tested and questioned，Thereby basing scientific progress on unreliable research data。However，It’s worth noting，Although scientists are limited by time、Resources and publication incentive system and other factors，It is true that complete replication experiments of other people’s research are rarely carried out，But it does not mean that there is no bet365 voucher design based on replication in scientific activities。Under the new perspective of scientific philosophy of new experimentalism and methodological pluralism，We can delve into the details of scientific practice，Understand how scientists deal with this problem。

　　Clear the bet365 voucher and meaning of repetition

 The new experimentalism that emerged in the philosophy of science in the 1980s，Shifting the traditional research perspective of theoretical superiority to vital bet365 voucher activities。Experiments are no longer simply regarded as an empirical tool for testing theories，Rather, it is rich in formal and cognitive meaning。Based on this position，We can divide repeated experiments into two categories according to their purpose: repeated experiments to test the existence of empirical phenomena、Repeated experiments to expand the robustness of bet365 voucher results。

Existence testing requires confirmation that the phenomenon is stable and not accidental，And confirm whether the bet365 voucher process and parameter settings are accurate or redundant。On the one hand，Researchers should conduct existence tests on their own research。Once the preliminary phenomena are obtained，The experiment should be repeated several times to ensure that the phenomenon can occur stably。After ruling out chance，Still need to check whether the bet365 voucher design contains unnoticed factors that can cause the phenomenon，This will cause a huge systematic bias。For example，In an experiment using fluorescent proteins to detect cell viability，It was later discovered that the complex used to regulate cell activity can itself produce fluorescence。Therefore，Process inspection requires small changes in commonly used bet365 voucher conditions，To avoid falling into the "standardization fallacy" - the stricter the bet365 voucher condition control，The less likely it is to obtain repeatable bet365 voucher phenomena。

Robustness expansion means seeking empirical evidence sufficient to provide multiple determination。For this purpose，Researchers should introduce greater changes in bet365 voucher design，Thereby expanding the scope of phenomena and conclusions。For example，In life science research，A common approach is to change different traits、bet365 voucher animals of species，Use different types of characterization instruments (such as microscopes and spectrometers with different principles), etc.。Due to the diversity of organisms and their molecular characteristics，Using different bet365 voucher objects and instruments to conduct one-by-one tests is usually an inevitable requirement to expand the robustness of the conclusions。

　　Exploring different methods of repeating bet365 voucher

The following introduces the specific bet365 voucher design that can achieve the two different goals of existence testing and robustness testing。Among them，About existence test，Mainly introduces the two types of repeated bet365 voucher designs, micro-repetitive experiments and large-scale repeated experiments；About robustness testing，Mainly introduces the two types of repeated experiment design: concept repeated experiments and data repeated experiments。

Microreplication experiment。Strict bet365 voucher control is usually required during the experiment，When setting relevant parameters and selecting bet365 voucher materials, you need to refer to the background knowledge provided by previous studies。However，When researchers use this background knowledge，Not applied directly without thinking，Instead, local "micro replication" is performed through a blank control experiment implemented before the intervention of the core experiment，To obtain the data background value for eliminating interference。For example，In in vitro protein binding assay，Considering the nature of the protein for the bet365 voucher environment (ion concentration、pH value, etc.) are very sensitive，The solution system must be tested for false positive control before binding assays are performed，and false negative control test for signal peptide tag。These two types of tests constitute repeated bet365 voucher testing of all background knowledge。In the above fluorescent protein research，The solution system in which active regulatory substances are added but cells are not added should be treated，Perform micro-repetitive testing experiments。Using this design can avoid false positive results in the core bet365 voucher part。Microreplicate experiments themselves as part of setting up and verifying bet365 voucher control conditions，Commonly found in general bet365 voucher research。Different from the usual understanding of repeated experiments，Microduplication is not a complete duplication of previous research，But it establishes a reproducible link between the new study and the original study，Constitutes an effective local existence test。This repetitive relationship can be reflected in the citation network。However，From the perspective of the way scientific research documents are written，Although the researcher used microduplication，But will avoid reporting repeated failures in practice，Only connect with previous studies that have repeated success。Therefore，Microreplication experiments do not have the function of screening and marking unrepeatable documents，Cannot further explain the reason for the failure。

Large-scale repeated experiments。Large-scale repeated experiments can test the existence of reliable research results in a specific field，Also monitor and report failures，Thus filling the functional shortcomings of micro-replication experiments to a certain extent。Currently，Many international organizations are testing the reproducibility of published literature in subject areas。For example，Professor of Psychology, University of Virginia、Nosek (B, one of the top ten people of the year in Nature magazine in 2015. A. Open Science Collaboration established by Nosek and others，Completed replication of hundreds of published psychology experiments in 2012。The results show，61% of studies failed to be successfully replicated。Since this project requires repeated experiments, the research team will maintain communication with the original author before and after completion，Thus helping to prevent repeated failures caused by imperfect bet365 voucher procedures，It is also possible to further examine the specific reasons for repeated failures through cooperation，Overall beneficial to improving the reliability of research in related fields。In addition，Large-scale repeated experiments help reduce the cost of repeated experiments through collaboration in the academic community，It is necessary to prevent researchers from not participating in repeated experiments due to the obstacles of the publication incentive system。In the long run，This helps reduce the proportion of unrepeatable documents，And be able to detect academic fraud in a timely manner。

Concept Repeat Experiment。Conceptual replication is common in psychology、Ecology field，Refers to the premise of deliberately changing the values ​​of core variables in the experiment，Attempting to reproduce variable relationships from previous studies，That is, the general theoretical hypothesis of the research is the same，The "small" hypothesis is similar but inconsistent。For example，In experiments in embodied cognitive psychology，The overall purpose of this type of research is to explore whether body perception affects cognition，Therefore, the roughness or hardness of the object can be used to form a set of different values ​​of the independent variables in the concept repeated experiments。Repeat the concept experiment by changing the value type of the variable，Making the bet365 voucher conclusions tenable in more general situations，Improved the robustness of research results。However，There are also some scholars who question the falsifiability of repeated experiments of concepts。They worry that only successful conceptual iterations will be used to support the original conclusion，The failed concept replication cannot be regarded as a strict reproduction of the original experiment，Therefore it cannot constitute effective falsification。Nevertheless，Repetition of successful concepts still has cognitive significance。

Data repeated experiments。In some special large-scale bet365 voucher studies，The original bet365 voucher data cannot be measured repeatedly，At this time, data replication can be used to verify the robustness of the research conclusions。For example，In research on climate change，We want to know if the temperature of the Earth's surface has actually increased over the past 60 years。But there are only a few research institutions that have carried out long-term effective observations (such as the Climate Research Center of the University of East Anglia、Raw data available from Met Office Hadley Centre)，And the data cannot be reacquired。For repeated inspection，NASA/Goddard Institute for Space Studies, New York、Different research groups such as the National Oceanic and Atmospheric Administration's National Climatic Data Center independently processed the original data in different ways (such as using different fitting methods、Delimit different areas to calculate average values, etc.)，Finally verified the robustness of this conclusion。Data duplication can make full use of such precious bet365 voucher resources，Problems in correcting data measurement，Ensure that the bet365 voucher results pass the robustness test。But，This type of research cannot be replicated in a strict sense，Therefore, it is also necessary to consider whether its conclusions can constitute a consistent scientific explanation with empirical evidence from other sources。

The four repeated experiment methods discussed above can achieve different purposes of existence or robustness testing，At the same time, they also have their own applicable scenarios and shortcomings。From Mitchell(S. Mitchell）、Cartwright (N. Cartwright，One should not pursue the gold standard of methodology in bet365 voucher design，But it should be based on the specific purpose of the research、Object、Assessed by multiple factors such as background knowledge、Improve and invent bet365 voucher methods with higher applicability。Therefore，The coexistence of multiple repeated bet365 voucher methods is necessary。

It’s worth noting，The repeated experiments introduced in this article are all from actual scientific research cases，But these are not complete replications of a study in the traditional sense，Replications that can be embedded in a general bet365 voucher design。This also answers the question "Why do scientists seem not to repeat experiments in the traditional sense"。In understanding reproducibility，We can not regard repeated experiments as additional to regular scientific research activities，But examine how to integrate it into bet365 voucher design ideas。In-depth understanding of bet365 voucher design strategies in cutting-edge scientific research，Can alleviate concerns about the reproducibility crisis in the scientific enterprise as a whole。

　(Author’s affiliation: Department of History of bet365 voucher, Tsinghua University)