Share:

Knowledge Base

What is the concept of robustness in statistics and how is it evaluated?

10/10/2023 | by Patrick Fischer, M.Sc., Founder & Data Scientist: FDS

In statistics, the concept of robustness refers to the ability of a statistical method to provide stable and reliable results even when the underlying assumptions are violated or the data contain outliers. Robust methods are less prone to extreme values ​​or violations of the assumptions and provide robust estimates or test results.

The robustness of a statistical method is usually assessed by comparison with other methods or by simulation experiments. There are several criteria that are taken into account when assessing robustness:

Influence analysis: The method is checked for how strongly individual observations or outliers influence the results. A robust method should be relatively insensitive to single observations that deviate greatly from the rest of the sample.

Comparison with non-robust methods: The robust method is compared with non-robust methods to show that it gives better or comparable results in violation of the assumptions or in the presence of outliers.

Simulation studies: The robustness of a method can be evaluated by simulating data with known properties, such as outliers or violations of assumptions. The results of the method are compared to the true values ​​or the results of other methods to assess their performance.

Theoretical Analysis: In some cases, mathematical or theoretical analysis can be used to assess the robustness of a method. This often involves examining the impact of data breaches on the properties of the method.

It is important to note that robustness is not an absolute property. One method may be more robust than others, but still potentially vulnerable to certain types of breaches or runaways. Therefore, it is advisable to consider different aspects of robustness in order to select the appropriate method for a particular statistical analysis.

Like (0)
Comment

What is the likelihood ratio statistic and how is it used?

10/10/2023 | by Patrick Fischer, M.Sc., Founder & Data Scientist: FDS

The likelihood ratio statistic (LR statistic) is a statistical measure used in hypothesis testing and model selection. It is based on the likelihood ratio, which assesses the relative fit of two competing statistical models.

To calculate the LR statistic, two models are compared: the null model and the alternative or extended model. The null model represents the null hypothesis, while the alternative model represents the alternative hypothesis. The Null Model is usually a simplified model that assumes that certain parameters or relationships do not exist. The Alternative Model includes additional parameters or provides an alternative representation of the data.

The first step in calculating LR statistics is to maximize the likelihood function for each model. The likelihood function measures the probability that the observed data will occur under the given model assumptions. The maximum likelihood is achieved by choosing the parameter values that provide the greatest probability for the observed data.

The LR statistic is then calculated by taking the logarithm of the quotient of the maximum likelihoods of the two models. In formal terms:

LR statistic = 2 * (log-likelihood of the alternative model - log-likelihood of the null model)

The LR statistic usually follows a chi-square distribution if the sample size is large enough and certain assumptions are met. The LR statistic can be used to perform hypothesis testing by setting critical thresholds for the LR statistic. If the calculated LR statistic exceeds the critical threshold, the null hypothesis can be rejected, and there is evidence that the Alternative Model provides a better fit to the data.

The LR statistic is also used in model selection to decide between different competing models. In this case, the model with the larger LR statistic is considered the better model because it provides a better fit to the data.

It is important to note that the use of the LR statistic depends on certain assumptions and preconditions, particularly the validity of the asymptotic distribution properties. In addition, the LR statistic should not be considered in isolation, but rather in conjunction with other information and considerations when interpreting the results.

Like (0)
Comment

Public relations in the company: The art of corporate communication

10/09/2023 | by Patrick Fischer, M.Sc., Founder & Data Scientist: FDS

Public relations (PR) is a key element of corporate communication that is crucial in today's business world. It goes far beyond the mere marketing of products or services and is concerned with strategically shaping and maintaining a company's public image. In this article, we will take a closer look at what PR really means in business.

The definition of PR in business

PR in business, also known as corporate public relations, is the process by which companies communicate specifically with different audiences in order to build trust, cultivate image and spread their messages effectively. These audiences can include customers, investors, employees, the media, regulators and the general public.

The role of PR in business

Image and reputation: One of the main objectives of PR in business is to create and maintain a positive image and reputation. This helps to gain the trust of customers and promote business growth

Crisis communication: PR plays a crucial role in dealing with crises and unexpected challenges. Communication during a crisis can maintain or restore stakeholder trust.

Media relations: Relationships with journalists and the media are a key part of corporate PR. The right media strategy can help generate positive coverage and disseminate important information.

Internal communication: PR also involves communicating internally to inform employees about company goals, changes and activities. Well-informed employees are often more engaged employees.

Customer communication: Communication with customers is a key area of PR. This includes providing information about products, services and company values.

Customer communication is a key area of PR.

The tools of PR in business

Corporate PR professionals use a variety of tools and tactics to achieve their goals:

Press releases: These are used to disseminate important company news and developments.

Media relations: PR professionals cultivate relationships with journalists and work to generate positive media coverage.

Social media: Platforms such as Twitter, Facebook and LinkedIn are used to facilitate communication with clients and stakeholders.

Crisis communication: PR professionals create crisis communication plans to respond effectively to unforeseen events.

Internal newsletters and communication tools: These are used to inform employees about company news and changes.

Conclusion

PR in business is an important discipline that helps shape and maintain a company's image and reputation. It is more than just advertising; it is strategic communication aimed at building relationships and gaining the trust of various stakeholders. Companies that use PR effectively usually have a better chance of long-term success and a strong position in their market.

Like (0)
Comment

The Role of Search Engine Marketing (SEM) in Digital Marketing

10/09/2023 | by Patrick Fischer, M.Sc., Founder & Data Scientist: FDS

In the age of the internet, search engine marketing (SEM) has become a central pillar of digital marketing. SEM encompasses a range of strategies and tactics that help companies be visible online, attract customers and achieve their business goals. In this article, we will highlight the critical role of SEM in Digital Marketing, explore the various aspects of this field and highlight best practices for success.

What is search engine marketing (SEM)?

SEM refers to marketing activities aimed at increasing the visibility of a website in search engine results. Essentially, it is about being found for relevant keywords when users search for information, products or services in search engines such as Google, Bing or Yahoo. SEM comprises two main components:

1. Search Engine Advertising (SEA): This refers to paid ads that appear in search results. Companies bid on keywords (search terms), and their ads are displayed when users search for those keywords.

2. Search Engine Optimisation (SEO): This refers to organic or non-paid results in search engines. SEO focuses on optimising the website to rank higher in search results.

The Importance of SEM in Digital Marketing

SEM plays a crucial role in Digital Marketing for several reasons:

1. High visibility: SEM allows businesses to be prominently placed in search engine results, leading to increased visibility and traffic.

2. Targeting: By choosing targeted keywords, businesses can reach their audiences accurately and target relevant users.

3. Quick results: With search engine advertising, businesses can get immediate results. As soon as a campaign is launched, ads are immediately placed and visible.

4. Performance analysis: SEM provides comprehensive data and analysis that allows businesses to measure and optimise the success of their campaigns.

5. Competitive advantage: Since most people use online search engines to find products or services, a strong presence in search results can provide a significant competitive advantage.

The components of SEM

SEM involves a variety of components and tactics:

1. Keyword research

Selecting the right keywords is critical. Businesses should research which keywords are used by their target audience and which are the most relevant.

2. Search Engine Advertising (SEA)

2. search engine advertising (SEA)

Companies create and place paid ads that appear in search results. This can be done via platforms such as Google Ads (formerly AdWords) and Bing Ads.

Search Engine Advertising (SEA).

3. search engine optimisation (SEO)

SEO involves optimising website content, structure and technology to rank better in organic search results. This includes on-page optimisation, off-page optimisation and technical SEO.

4. Landing Pages

Landing pages are specially designed pages that users arrive at after clicking on an ad or search result. They should contain relevant information and clear calls to action

5. Ad optimisation

Ad optimisation involves regularly reviewing and adjusting ad copy, keywords and bids to maximise performance.

Best practices for SEM success

To be successful in SEM, businesses should follow some best practices:

1. Continuous monitoring and optimisation: SEM requires continuous attention and adjustment. Regular review and optimisation of ads and keywords are critical.

2. Quality awareness: Be sure to generate high-quality traffic. This means making sure your ads contain relevant keywords and lead to relevant landing pages

3. audience analysis: understand your target audience, their needs and behaviours to choose effective ads and keywords.

4. Budget management: Set a realistic budget and manage it carefully to ensure you achieve your goals.

5. Mobile optimisation: As more and more users use mobile devices, ads and landing pages should be optimised for mobile devices.

Summary

Search engine marketing (SEM) is an indispensable part of digital marketing and offers businesses the opportunity to be visible online, reach target audiences and achieve business goals. With the right keyword research, high-quality ads and continuous optimisation, businesses can reap the benefits of SEM and strengthen their presence in search engine results. In an age where online search engines are the first port of call for information, an effective SEM strategy can have a significant impact on a company's success.The Role of Search Engine Marketing (SEM) in Digital Marketing

In the age of the internet, search engine marketing (SEM) has become a central pillar of digital marketing. SEM encompasses a range of strategies and tactics that help companies be visible online, attract customers and achieve their business goals. In this article, we will highlight the critical role of SEM in Digital Marketing, explore the various aspects of this field and highlight best practices for success.

What is search engine marketing (SEM)?

SEM refers to marketing activities aimed at increasing the visibility of a website in search engine results. Essentially, it is about being found for relevant keywords when users search for information, products or services in search engines such as Google, Bing or Yahoo. SEM comprises two main components:

1. Search Engine Advertising (SEA): This refers to paid ads that appear in search results. Companies bid on keywords (search terms), and their ads are displayed when users search for those keywords.

2. Search Engine Optimisation (SEO): This refers to organic or non-paid results in search engines. SEO focuses on optimising the website to rank higher in search results.

Companies create and serve paid ads that appear in search results. This can be done via platforms such as Google Ads (formerly AdWords) and Bing Ads.

3. search engine optimisation (SEO)

SEO involves optimising website content, structure and technology to rank better in organic search results. This includes on-page optimisation, off-page optimisation and technical SEO.

4. Landing Pages

Landing pages are specially designed pages that users arrive at after clicking on an ad or search result. They should contain relevant information and clear calls to action

5. Ad optimisation

Ad optimisation involves regularly reviewing and adjusting ad copy, keywords and bids to maximise performance.

Best practices for SEM success

To be successful in SEM, businesses should follow some best practices:

1. Continuous monitoring and optimisation: SEM requires continuous attention and adjustment. Regular review and optimisation of ads and keywords are critical.

2. Quality awareness: Be sure to generate high-quality traffic. This means ensuring that your ads contain relevant keywords and lead to relevant landing pages.

3. audience analysis: understand your target audience, their needs and behaviours to choose effective ads and keywords.

4. Budget management: Set a realistic budget and manage it carefully to ensure you achieve your goals.

5. Mobile optimisation: As more and more users use mobile devices, ads and landing pages should be optimised for mobile devices.

Summary

Search engine marketing (SEM) is an indispensable part of digital marketing and offers businesses the opportunity to be visible online, reach target audiences and achieve business goals. With the right keyword research, high-quality ads and continuous optimisation, businesses can reap the benefits of SEM and strengthen their presence in search engine results. At a time when online search engines are the first port of call for information, an effective SEM strategy can have a significant impact on a company's success.

Like (0)
Comment

How to implement stratified sampling in practice?

10/09/2023 | by Patrick Fischer, M.Sc., Founder & Data Scientist: FDS

Stratified sampling is a statistical technique that divides the total population into distinct homogeneous groups, or strata. A sample is then taken from each stratum to obtain a representative sample of the overall population. The implementation of stratified sampling in practice usually involves the following steps:

Defining the Strata: Identify the relevant characteristics or variables by which you want to divide the overall population into homogeneous groups. For example, you could stratify by age, gender, income, or geographic location.

Determining sample size: Decide how many elements you want to draw from each stratum. The sample size can be proportional to the size of the stratum or other criteria to ensure that each stratum is adequately represented.

Random sampling within strata: Run a random sample within each stratum to obtain the required number of elements. This can be done by simply drawing random numbers or using computerized random number generators.

Collect data: Collect the relevant data for each selected item in the sample. Make sure you document the data carefully and maintain attribution to the appropriate strata for later analysis.

Analyze Data: Analyze the collected data using statistical methods and techniques appropriate to your research goals. Note the stratum of each element to extrapolate the results to the total population and derive accurate estimates.

Stratified sampling is a powerful tool for ensuring that different subgroups of a population are adequately represented in a sample. This method can reduce distortion and provide more meaningful results.

Like (0)
Comment

Our offer to you:

Media & PR Database 2024

Only for a short time at a special price: The media and PR database with 2024 with information on more than 21,000 newspaper, magazine and radio editorial offices and much more.

Newsletter

Subscribe to our newsletter and receive the latest news & information on promotions: