Difference between revisions of "10 Unexpected Pragmatic Free Trial Meta Tips"

From
Jump to: navigation, search
m
m
 
(5 intermediate revisions by 5 users not shown)
Line 1: Line 1:
Pragmatic Free Trial Meta<br><br>Pragmatic Free Trial Meta is a non-commercial open data platform and infrastructure that supports research on pragmatic trials. It shares clean trial data and ratings using PRECIS-2, allowing for multiple and diverse meta-epidemiological studies to evaluate the effect of treatment on trials with different levels of pragmatism as well as other design features.<br><br>Background<br><br>Pragmatic trials provide real-world evidence that can be used to make clinical decisions. The term "pragmatic", however, is not used in a consistent manner and its definition and evaluation need further clarification. Pragmatic trials are designed to guide the practice of clinical medicine and policy choices, rather than prove a physiological or clinical hypothesis. A pragmatic study should aim to be as similar to the real-world clinical environment as is possible, including the participation of participants, setting up and design as well as the execution of the intervention, and the determination and analysis of the outcomes, and primary analyses. This is a major distinction between explanatory trials as described by Schwartz and Lellouch1 that are designed to confirm the hypothesis in a more thorough manner.<br><br>The trials that are truly practical should avoid attempting to blind participants or healthcare professionals, as this may lead to bias in estimates of the effect of treatment. Pragmatic trials will also recruit patients from different healthcare settings to ensure that their results can be applied to the real world.<br><br>Furthermore, trials that are pragmatic must concentrate on outcomes that are important to patients, like quality of life and functional recovery. This is particularly important when trials involve surgical procedures that are invasive or may have dangerous adverse impacts. The CRASH trial29 compared a 2-page report with an electronic monitoring system for patients in hospitals with chronic heart failure. The catheter trial28, however was based on symptomatic catheter-related urinary tract infections as its primary outcome.<br><br>In addition to these aspects, pragmatic trials should minimize the trial's procedures and requirements for data collection to reduce costs. Additionally the aim of pragmatic trials is to make their results as relevant to real-world clinical practice as is possible. This can be achieved by ensuring that their analysis is based on an intention-to treat approach (as described within CONSORT extensions).<br><br>Many RCTs which do not meet the criteria for pragmatism but have features that are in opposition to pragmatism, have been published in journals of various kinds and incorrectly labeled pragmatic. This could lead to misleading claims of pragmatism and the use of the term needs to be standardized. The creation of the PRECIS-2 tool, which offers an objective and standard assessment of pragmatic features,  프라그마틱 슬롯 사이트; [https://getsocialsource.com/story3385216/you-will-meet-the-steve-jobs-of-the-pragmatic-slot-recommendations-industry https://getsocialsource.com/story3385216/You-will-meet-the-steve-jobs-of-the-pragmatic-slot-recommendations-industry], is a good first step.<br><br>Methods<br><br>In a practical study the aim is to inform clinical or policy decisions by demonstrating how an intervention can be integrated into routine care in real-world situations. This is distinct from explanation trials that test hypotheses about the cause-effect relationship in idealised situations. In this way, pragmatic trials could have less internal validity than explanation studies and are more susceptible to biases in their design analysis, conduct, and design. Despite these limitations, pragmatic trials can provide valuable information to decision-making in healthcare.<br><br>The PRECIS-2 tool evaluates an RCT on 9 domains, with scores ranging from 1 to 5 (very pragmatist). In this study, the recruitment, organisation, flexibility: delivery and follow-up domains were awarded high scores, but the primary outcome and  [https://pragmatickr-com97631.blogdon.net/the-ultimate-cheat-sheet-on-live-casino-46003646 프라그마틱 데모] the procedure for missing data were not at the pragmatic limit. This suggests that a trial can be designed with good pragmatic features, without harming the quality of the trial.<br><br>However, it's difficult to determine how practical a particular trial is, since pragmaticity is not a definite attribute; some aspects of a study can be more pragmatic than others. A trial's pragmatism can be affected by changes to the protocol or the logistics during the trial. Additionally 36% of 89 pragmatic trials identified by Koppenaal and colleagues were placebo-controlled, or conducted prior to licensing and most were single-center. They are not in line with the standard practice and are only referred to as pragmatic if their sponsors accept that such trials are not blinded.<br><br>Additionally, a typical feature of pragmatic trials is that researchers try to make their results more valuable by studying subgroups of the sample. However, this often leads to unbalanced results and  [https://atozbookmark.com/story17971891/why-the-biggest-myths-concerning-pragmatic-korea-could-actually-be-accurate 프라그마틱 슬롯무료] 슈가러쉬 ([https://bookmarkshome.com/story3603499/15-unexpected-facts-about-pragmatic-free-trial-that-you-never-knew Highly recommended Web-site]) lower statistical power, increasing the risk of either not detecting or incorrectly detecting differences in the primary outcome. In the case of the pragmatic trials included in this meta-analysis, this was a serious issue since the secondary outcomes were not adjusted to account for variations in the baseline covariates.<br><br>In addition, pragmatic studies can present challenges in the collection and interpretation safety data. It is because adverse events are typically self-reported, and therefore are prone to delays, errors or coding variations. It is important to improve the accuracy and quality of the results in these trials.<br><br>Results<br><br>While the definition of pragmatism doesn't require that clinical trials be 100% pragmatist there are benefits to including pragmatic components in trials. These include:<br><br>By including routine patients, the results of the trial are more easily translated into clinical practice. However, pragmatic studies can also have disadvantages. For instance, the right kind of heterogeneity can allow a study to generalize its results to different patients and settings; however the wrong type of heterogeneity may reduce the assay's sensitiveness and consequently reduce the power of a trial to detect small treatment effects.<br><br>A variety of studies have attempted to categorize pragmatic trials using various definitions and scoring methods. Schwartz and Lellouch1 have developed a framework that can discern between explanation-based studies that support a physiological hypothesis or clinical hypothesis, and pragmatic studies that inform the selection of appropriate treatments in real world clinical practice. The framework was comprised of nine domains evaluated on a scale of 1-5 with 1 being more explanatory while 5 being more pragmatic. The domains included recruitment of intervention, setting up, delivery of intervention, flexible adhering to the program and primary analysis.<br><br>The initial PRECIS tool3 included similar domains and an assessment scale ranging from 1 to 5. Koppenaal and colleagues10 created an adaptation of this assessment, known as the Pragmascope, that was easier to use for systematic reviews. They found that pragmatic reviews scored higher across all domains, however they scored lower in the primary analysis domain.<br><br>The difference in the primary analysis domain could be due to the fact that most pragmatic trials process their data in the intention to treat method while some explanation trials do not. The overall score for pragmatic systematic reviews was lower when the domains of organisation, flexible delivery and follow-up were merged.<br><br>It is important to remember that a pragmatic study does not mean that a trial is of poor quality. In fact, there is a growing number of clinical trials which use the term "pragmatic" either in their title or abstract (as defined by MEDLINE but which is neither sensitive nor precise). These terms may signal a greater understanding of pragmatism in titles and abstracts, but it's not clear whether this is evident in content.<br><br>Conclusions<br><br>As appreciation for the value of real-world evidence becomes increasingly commonplace the pragmatic trial has gained traction in research. They are randomized trials that compare real world treatment options with clinical trials in development. They involve patient populations that are more similar to those who receive treatment in regular medical care. This approach has the potential to overcome the limitations of observational research which include the biases associated with reliance on volunteers, and the limited availability and the variability of coding in national registries.<br><br>Other benefits of pragmatic trials include the possibility of using existing data sources, and a higher chance of detecting meaningful changes than traditional trials. However, these trials could be prone to limitations that compromise their reliability and generalizability. For example the rates of participation in some trials might be lower than anticipated due to the healthy-volunteer influence and incentives to pay or compete for participants from other research studies (e.g. industry trials). The requirement to recruit participants quickly limits the sample size and impact of many pragmatic trials. In addition certain pragmatic trials don't have controls to ensure that the observed differences are not due to biases in the conduct of trials.<br><br>The authors of the Pragmatic Free Trial Meta identified RCTs published from 2022 to 2022 that self-described themselves as pragmatic. The PRECIS-2 tool was employed to determine the pragmatism of these trials. It covers areas like eligibility criteria as well as recruitment flexibility and adherence to intervention and follow-up. They discovered that 14 trials scored highly pragmatic or pragmatic (i.e. scoring 5 or above) in at least one of these domains.<br><br>Trials that have high pragmatism scores tend to have more criteria for eligibility than conventional RCTs. They also have patients from a variety of hospitals. The authors argue that these characteristics can help make pragmatic trials more effective and relevant to everyday clinical practice, however they don't necessarily mean that a trial conducted in a pragmatic manner is free from bias. The pragmatism principle is not a fixed characteristic and a test that does not have all the characteristics of an explicative study can still produce valuable and valid results.
+
Pragmatic Free Trial Meta<br><br>Pragmatic Free Trial Meta is a non-commercial, open data platform and infrastructure that supports research on pragmatic trials. It collects and distributes clean trial data, ratings, and evaluations using PRECIS-2. This permits a variety of meta-epidemiological analyses to evaluate the effects of treatment across trials of different levels of pragmatism.<br><br>Background<br><br>Pragmatic trials provide real-world evidence that can be used to make clinical decisions. However, the usage of the term "pragmatic" is not uniform and its definition and 라이브 카지노 ([http://8.134.38.106:3000/pragmaticplay3686 Click on 8.134.38.106]) evaluation requires clarification. The purpose of pragmatic trials is to guide clinical practice and policy decisions, rather than confirm an hypothesis that is based on a clinical or physiological basis. A pragmatic trial should aim to be as close as possible to the real-world clinical practice that include recruitment of participants, setting, designing, implementation and delivery of interventions, determination and [http://109.195.52.92:3000/pragmaticplay0145 프라그마틱 체험] analysis outcomes, and primary analyses. This is a significant distinction from explanatory trials (as described by Schwartz and Lellouch1), which are intended to provide a more complete confirmation of the hypothesis.<br><br>Truely pragmatic trials should not conceal participants or clinicians. This can lead to a bias in the estimates of treatment effects. Practical trials also involve patients from different healthcare settings to ensure that their outcomes can be compared to the real world.<br><br>Finally the focus of pragmatic trials should be on outcomes that are important to patients, like quality of life or functional recovery. This is particularly important in trials that require surgical procedures that are invasive or may have serious adverse effects. The CRASH trial29 compared a 2-page report with an electronic monitoring system for patients in hospitals with chronic heart failure. The catheter trial28 on the other hand utilized symptomatic catheter-related urinary tract infections as its primary outcome.<br><br>In addition to these aspects pragmatic trials should also reduce trial procedures and data-collection requirements to cut costs and time commitments. Finally pragmatic trials should try to make their findings as applicable to clinical practice as possible by making sure that their primary method of analysis follows the intention-to treat approach (as described in CONSORT extensions for pragmatic trials).<br><br>Many RCTs that do not meet the criteria for pragmatism however, they have characteristics that are contrary to pragmatism, have been published in journals of different types and incorrectly labeled pragmatic. This can result in misleading claims of pragmaticity and the usage of the term needs to be standardized. The development of a PRECIS-2 tool that offers an objective and standardized assessment of pragmatic features is the first step.<br><br>Methods<br><br>In a pragmatic research study, the goal is to inform policy or clinical decisions by demonstrating how an intervention can be integrated into routine treatment in real-world contexts. This is different from explanatory trials that test hypotheses about the causal-effect relationship in idealized situations. Therefore, pragmatic trials could have less internal validity than explanatory trials and may be more susceptible to bias in their design, conduct, and analysis. Despite their limitations, pragmatic research can provide valuable information to make decisions in the healthcare context.<br><br>The PRECIS-2 tool scores an RCT on 9 domains, ranging from 1 to 5 (very pragmatist). In this study, the recruit-ment organisation, flexibility: delivery and follow-up domains were awarded high scores, but the primary outcome and the method for missing data fell below the limit of practicality. This indicates that a trial can be designed with good practical features, yet not damaging the quality.<br><br>However, it's difficult to judge how practical a particular trial is since pragmaticity is not a definite attribute; some aspects of a trial can be more pragmatic than others. A trial's pragmatism could be affected by changes to the protocol or the logistics during the trial. Additionally 36% of 89 pragmatic trials identified by Koppenaal and colleagues were placebo-controlled, or conducted prior to licensing and most were single-center. They aren't in line with the standard practice and  프라그마틱 무료체험 메타 ([http://47.100.81.115/pragmaticplay3520/jonna2002/wiki/5-Killer-Quora-Answers-To-Pragmatic-Kr 47.100.81.115]) are only considered pragmatic if their sponsors agree that such trials aren't blinded.<br><br>Furthermore, a common feature of pragmatic trials is that researchers try to make their results more meaningful by analysing subgroups of the trial. This can lead to unbalanced results and lower statistical power, which increases the likelihood of missing or misinterpreting the results of the primary outcome. In the instance of the pragmatic trials included in this meta-analysis, this was a major issue because the secondary outcomes weren't adjusted for variations in baseline covariates.<br><br>Additionally practical trials can have challenges with respect to the collection and interpretation of safety data. This is due to the fact that adverse events are usually self-reported and are susceptible to reporting delays, inaccuracies or coding deviations. It is therefore important to enhance the quality of outcomes ascertainment in these trials, in particular by using national registries instead of relying on participants to report adverse events in the trial's own database.<br><br>Results<br><br>While the definition of pragmatism may not mean that trials must be 100 percent pragmatic, there are benefits to including pragmatic components in clinical trials. These include:<br><br>Enhancing sensitivity to issues in the real world which reduces cost and size of the study as well as allowing trial results to be more quickly implemented into clinical practice (by including patients from routine care). However, pragmatic trials have disadvantages. For example, the right kind of heterogeneity can allow the trial to apply its results to many different patients and settings; however the wrong kind of heterogeneity could reduce assay sensitiveness and consequently reduce the power of a study to detect even minor effects of treatment.<br><br>A number of studies have attempted to classify pragmatic trials using various definitions and scoring systems. Schwartz and Lellouch1 developed a framework to distinguish between research studies that prove a clinical or physiological hypothesis as well as pragmatic trials that inform the selection of appropriate therapies in real-world clinical practice. The framework consisted of nine domains scored on a 1-5 scale, with 1 being more informative and 5 being more pragmatic. The domains included recruitment, setting up, delivery of intervention, flexible adherence and primary analysis.<br><br>The initial PRECIS tool3 featured similar domains and a scale of 1 to 5. Koppenaal and colleagues10 developed an adaptation of this assessment dubbed the Pragmascope that was simpler to use in systematic reviews. They found that pragmatic systematic reviews had a higher average score in most domains, but lower scores in the primary analysis domain.<br><br>The difference in the primary analysis domains could be explained by the way that most pragmatic trials approach data. Some explanatory trials, however don't. The overall score was lower for pragmatic systematic reviews when the domains on the organization, flexibility of delivery and follow-up were merged.<br><br>It is important to understand that a pragmatic trial doesn't necessarily mean a low quality trial, and indeed there is an increasing rate of clinical trials (as defined by MEDLINE search, however this is neither specific or sensitive) which use the word 'pragmatic' in their abstract or title. The use of these words in abstracts and titles could indicate a greater understanding of the importance of pragmatism however, it is not clear if this is manifested in the contents of the articles.<br><br>Conclusions<br><br>As the importance of real-world evidence grows widespread, pragmatic trials have gained traction in research. They are randomized trials that evaluate real-world treatment options with new treatments that are being developed. They involve patient populations that are more similar to those who receive treatment in regular medical care. This approach can help overcome the limitations of observational research, such as the biases associated with reliance on volunteers, and the limited availability and the variability of coding in national registries.<br><br>Pragmatic trials also have advantages, including the ability to leverage existing data sources and a higher chance of detecting significant differences from traditional trials. However, pragmatic trials may have some limitations that limit their credibility and generalizability. For example, participation rates in some trials may be lower than anticipated due to the healthy-volunteer influence and incentives to pay or compete for participants from other research studies (e.g.,  [http://123.60.103.97:3000/pragmaticplay4581 프라그마틱 정품확인방법] industry trials). The need to recruit individuals quickly restricts the sample size and the impact of many practical trials. Additionally, some pragmatic trials don't have controls to ensure that the observed differences aren't due to biases in the conduct of trials.<br><br>The authors of the Pragmatic Free Trial Meta identified RCTs that were published between 2022 and 2022 that self-described as pragmatic. They assessed pragmatism by using the PRECIS-2 tool that includes the domains eligibility criteria, recruitment, flexibility in adherence to intervention and follow-up. They discovered that 14 of the trials scored highly or pragmatic sensible (i.e., scoring 5 or more) in one or more of these domains and that the majority of them were single-center.<br><br>Studies with high pragmatism scores are likely to have more lenient criteria for eligibility than traditional RCTs. They also have patients from a variety of hospitals. The authors argue that these characteristics could make the pragmatic trials more relevant and relevant to everyday practice, but they do not necessarily guarantee that a trial using a pragmatic approach is completely free of bias. The pragmatism principle is not a fixed attribute the test that does not have all the characteristics of an explicative study may still yield valuable and valid results.

Latest revision as of 13:38, 26 December 2024

Pragmatic Free Trial Meta

Pragmatic Free Trial Meta is a non-commercial, open data platform and infrastructure that supports research on pragmatic trials. It collects and distributes clean trial data, ratings, and evaluations using PRECIS-2. This permits a variety of meta-epidemiological analyses to evaluate the effects of treatment across trials of different levels of pragmatism.

Background

Pragmatic trials provide real-world evidence that can be used to make clinical decisions. However, the usage of the term "pragmatic" is not uniform and its definition and 라이브 카지노 (Click on 8.134.38.106) evaluation requires clarification. The purpose of pragmatic trials is to guide clinical practice and policy decisions, rather than confirm an hypothesis that is based on a clinical or physiological basis. A pragmatic trial should aim to be as close as possible to the real-world clinical practice that include recruitment of participants, setting, designing, implementation and delivery of interventions, determination and 프라그마틱 체험 analysis outcomes, and primary analyses. This is a significant distinction from explanatory trials (as described by Schwartz and Lellouch1), which are intended to provide a more complete confirmation of the hypothesis.

Truely pragmatic trials should not conceal participants or clinicians. This can lead to a bias in the estimates of treatment effects. Practical trials also involve patients from different healthcare settings to ensure that their outcomes can be compared to the real world.

Finally the focus of pragmatic trials should be on outcomes that are important to patients, like quality of life or functional recovery. This is particularly important in trials that require surgical procedures that are invasive or may have serious adverse effects. The CRASH trial29 compared a 2-page report with an electronic monitoring system for patients in hospitals with chronic heart failure. The catheter trial28 on the other hand utilized symptomatic catheter-related urinary tract infections as its primary outcome.

In addition to these aspects pragmatic trials should also reduce trial procedures and data-collection requirements to cut costs and time commitments. Finally pragmatic trials should try to make their findings as applicable to clinical practice as possible by making sure that their primary method of analysis follows the intention-to treat approach (as described in CONSORT extensions for pragmatic trials).

Many RCTs that do not meet the criteria for pragmatism however, they have characteristics that are contrary to pragmatism, have been published in journals of different types and incorrectly labeled pragmatic. This can result in misleading claims of pragmaticity and the usage of the term needs to be standardized. The development of a PRECIS-2 tool that offers an objective and standardized assessment of pragmatic features is the first step.

Methods

In a pragmatic research study, the goal is to inform policy or clinical decisions by demonstrating how an intervention can be integrated into routine treatment in real-world contexts. This is different from explanatory trials that test hypotheses about the causal-effect relationship in idealized situations. Therefore, pragmatic trials could have less internal validity than explanatory trials and may be more susceptible to bias in their design, conduct, and analysis. Despite their limitations, pragmatic research can provide valuable information to make decisions in the healthcare context.

The PRECIS-2 tool scores an RCT on 9 domains, ranging from 1 to 5 (very pragmatist). In this study, the recruit-ment organisation, flexibility: delivery and follow-up domains were awarded high scores, but the primary outcome and the method for missing data fell below the limit of practicality. This indicates that a trial can be designed with good practical features, yet not damaging the quality.

However, it's difficult to judge how practical a particular trial is since pragmaticity is not a definite attribute; some aspects of a trial can be more pragmatic than others. A trial's pragmatism could be affected by changes to the protocol or the logistics during the trial. Additionally 36% of 89 pragmatic trials identified by Koppenaal and colleagues were placebo-controlled, or conducted prior to licensing and most were single-center. They aren't in line with the standard practice and 프라그마틱 무료체험 메타 (47.100.81.115) are only considered pragmatic if their sponsors agree that such trials aren't blinded.

Furthermore, a common feature of pragmatic trials is that researchers try to make their results more meaningful by analysing subgroups of the trial. This can lead to unbalanced results and lower statistical power, which increases the likelihood of missing or misinterpreting the results of the primary outcome. In the instance of the pragmatic trials included in this meta-analysis, this was a major issue because the secondary outcomes weren't adjusted for variations in baseline covariates.

Additionally practical trials can have challenges with respect to the collection and interpretation of safety data. This is due to the fact that adverse events are usually self-reported and are susceptible to reporting delays, inaccuracies or coding deviations. It is therefore important to enhance the quality of outcomes ascertainment in these trials, in particular by using national registries instead of relying on participants to report adverse events in the trial's own database.

Results

While the definition of pragmatism may not mean that trials must be 100 percent pragmatic, there are benefits to including pragmatic components in clinical trials. These include:

Enhancing sensitivity to issues in the real world which reduces cost and size of the study as well as allowing trial results to be more quickly implemented into clinical practice (by including patients from routine care). However, pragmatic trials have disadvantages. For example, the right kind of heterogeneity can allow the trial to apply its results to many different patients and settings; however the wrong kind of heterogeneity could reduce assay sensitiveness and consequently reduce the power of a study to detect even minor effects of treatment.

A number of studies have attempted to classify pragmatic trials using various definitions and scoring systems. Schwartz and Lellouch1 developed a framework to distinguish between research studies that prove a clinical or physiological hypothesis as well as pragmatic trials that inform the selection of appropriate therapies in real-world clinical practice. The framework consisted of nine domains scored on a 1-5 scale, with 1 being more informative and 5 being more pragmatic. The domains included recruitment, setting up, delivery of intervention, flexible adherence and primary analysis.

The initial PRECIS tool3 featured similar domains and a scale of 1 to 5. Koppenaal and colleagues10 developed an adaptation of this assessment dubbed the Pragmascope that was simpler to use in systematic reviews. They found that pragmatic systematic reviews had a higher average score in most domains, but lower scores in the primary analysis domain.

The difference in the primary analysis domains could be explained by the way that most pragmatic trials approach data. Some explanatory trials, however don't. The overall score was lower for pragmatic systematic reviews when the domains on the organization, flexibility of delivery and follow-up were merged.

It is important to understand that a pragmatic trial doesn't necessarily mean a low quality trial, and indeed there is an increasing rate of clinical trials (as defined by MEDLINE search, however this is neither specific or sensitive) which use the word 'pragmatic' in their abstract or title. The use of these words in abstracts and titles could indicate a greater understanding of the importance of pragmatism however, it is not clear if this is manifested in the contents of the articles.

Conclusions

As the importance of real-world evidence grows widespread, pragmatic trials have gained traction in research. They are randomized trials that evaluate real-world treatment options with new treatments that are being developed. They involve patient populations that are more similar to those who receive treatment in regular medical care. This approach can help overcome the limitations of observational research, such as the biases associated with reliance on volunteers, and the limited availability and the variability of coding in national registries.

Pragmatic trials also have advantages, including the ability to leverage existing data sources and a higher chance of detecting significant differences from traditional trials. However, pragmatic trials may have some limitations that limit their credibility and generalizability. For example, participation rates in some trials may be lower than anticipated due to the healthy-volunteer influence and incentives to pay or compete for participants from other research studies (e.g., 프라그마틱 정품확인방법 industry trials). The need to recruit individuals quickly restricts the sample size and the impact of many practical trials. Additionally, some pragmatic trials don't have controls to ensure that the observed differences aren't due to biases in the conduct of trials.

The authors of the Pragmatic Free Trial Meta identified RCTs that were published between 2022 and 2022 that self-described as pragmatic. They assessed pragmatism by using the PRECIS-2 tool that includes the domains eligibility criteria, recruitment, flexibility in adherence to intervention and follow-up. They discovered that 14 of the trials scored highly or pragmatic sensible (i.e., scoring 5 or more) in one or more of these domains and that the majority of them were single-center.

Studies with high pragmatism scores are likely to have more lenient criteria for eligibility than traditional RCTs. They also have patients from a variety of hospitals. The authors argue that these characteristics could make the pragmatic trials more relevant and relevant to everyday practice, but they do not necessarily guarantee that a trial using a pragmatic approach is completely free of bias. The pragmatism principle is not a fixed attribute the test that does not have all the characteristics of an explicative study may still yield valuable and valid results.