Which of the following is essential for effective data visualization in dashboards?

Connected data sources are essential for effective data visualization in dashboards because they allow for the integration and real-time updating of information from multiple systems or databases. By having connected data sources, users can ensure that the visual representations are based on the most current and relevant data, facilitating informed decision-making. This connectivity enables dynamic interaction with the data, allowing users to explore various dimensions and insights without being hindered by outdated or static information.

In contrast, the other options do not contribute positively to the effectiveness of dashboards. Complex formulas can complicate data interpretation and may distract users from the core insights. Too many datasets can overcrowd a dashboard, making it overwhelming and difficult for users to extract meaningful information. Static data representations lack the responsiveness and interactivity that are key to understanding data trends and patterns, resulting in missed opportunities for deeper insights. Therefore, connected data sources are fundamental to creating impactful and user-friendly visualizations in dashboards.