Crazy Egg - Detailed Review
Website Tools
Crazy Egg - Product Overview
Overview
Crazy Egg is a versatile website analytics and optimization tool that helps businesses improve their online presence and user engagement. Here’s a brief overview of its primary function, target audience, and key features:
Primary Function
Crazy Egg is designed to analyze how visitors interact with your website, providing valuable insights to optimize user experience, increase conversions, and fix usability issues. It achieves this through various visual reports and analytics tools.
Target Audience
Crazy Egg’s target audience includes a wide range of businesses, particularly those in industries such as eCommerce, retail, education, and more. The majority of its customers are small to medium-sized businesses, with a significant number of companies having 0-9 employees, followed by those with 20-49 employees, and then 100-249 employees.
Key Features
Heatmaps, Scroll Maps, and Click Reports
These tools show where users click, scroll, and engage with different elements on your web pages, helping you identify areas of high and low engagement.
Session Recordings
This feature allows you to watch individual user sessions to see how visitors interact with your site, including where they get stuck or drop off.
A/B Testing
Crazy Egg enables you to conduct split tests to compare different versions of your website and determine which changes improve conversions.
Form Analytics
This tool helps you analyze how users interact with forms, identifying where they struggle or drop off, which can be crucial for optimizing form completion rates.
Error Detection
It identifies and helps you fix errors on your website that might be preventing visitors from converting.
Traffic Source Analysis
You can compare and analyze traffic from different marketing channels to see which channels perform best for each page of your site.
Surveys and Feedback
Crazy Egg allows you to gather direct feedback from your customers through surveys, helping you make informed decisions based on real user insights.
Integrations
The tool integrates with popular services like Shopify, WordPress, and Google Analytics, making it easier to combine visual data with quantitative data for comprehensive insights.
Conclusion
Overall, Crazy Egg is a powerful tool for businesses looking to enhance their website performance, user engagement, and conversion rates through data-driven decisions.
Crazy Egg - User Interface and Experience
User Interface of Crazy Egg
The user interface of Crazy Egg is known for its simplicity and user-friendliness. Here are some key aspects that highlight its ease of use and overall user experience:Ease of Use
Setting up Crazy Egg is a straightforward process that can be completed in just a few minutes. It involves a basic 3-step process: signing up, adding a new snapshot by entering the URL of the page you want to track, and adding the tracking code to your website. For users of WordPress, there is a plugin that simplifies this process even further.Interface Layout
The platform focuses primarily on heatmapping, which makes the interface clean and easy to navigate. Crazy Egg offers four different views, including the Heatmap View, which visually represents where users are clicking, scrolling, and moving their mouse on your website. This visual representation helps in quickly identifying hotspots and areas that need improvement.Key Features
- Heatmaps: Crazy Egg provides click heatmaps, scroll heatmaps, and mouse movement heatmaps. These heatmaps are color-coordinated, making it easy to see where users are engaging the most.
- Session Recordings: Users can record and replay individual user sessions, which provides valuable insights into how visitors interact with the website. This feature helps in identifying areas where users encounter difficulties and where they find value.
- A/B Testing: The platform allows for easy A/B testing, enabling you to compare different versions of your website or specific elements to determine which changes lead to better user engagement and conversion rates.
User Experience
The overall user experience with Crazy Egg is positive due to its intuitive interface. Here are a few points that contribute to this:- Visual Insights: The heatmaps and session recordings provide clear, visual insights into user behavior, making it easier to make data-driven decisions to optimize the website.
- Simple Setup and Use: The setup process is quick, and the interface is easy to use, even for those who are not tech-savvy.
- Detailed Analysis: Crazy Egg offers detailed analysis of user behavior, including click tracking, scroll depth, and mouse movement. This helps in enhancing the user experience by optimizing the layout, navigation, and content placement.
Engagement and Feedback
While Crazy Egg excels in heatmapping and A/B testing, it also integrates with Survey Monkey to gather qualitative feedback from users. However, this feature is still developing and may not be as seamless as some users would like. In summary, Crazy Egg’s user interface is designed to be user-friendly, with a focus on providing clear and actionable insights into user behavior. Its ease of use and the wealth of visual data it provides make it an invaluable tool for optimizing website design and improving the overall user experience. Crazy Egg - Key Features and Functionality
Crazy Egg Overview
Crazy Egg is a comprehensive website analytics tool that offers a variety of features to help you analyze and improve user behavior on your website. Here are the main features and how they work:
Analysis Features
- Conversion Opportunities: This feature identifies poorly performing or problematic areas of your web page, helping you pinpoint where users are dropping off or encountering issues. It provides insights into areas that need improvement to enhance conversion rates.
- Side-By-Side Analysis: This allows you to overlay heatmaps on top of existing web pages, enabling a direct comparison of different versions or devices. For example, you can compare the behavior of mobile and desktop users side by side.
- Mobile Device Analysis: This feature optimizes data collection to provide insights about visitors using mobile web browsers. It helps you understand how mobile users interact with your site, which is crucial for mobile optimization.
- Data Quantification: This feature contextualizes web visitor behavior by going beyond pure data points and statistics. It provides a deeper analysis of user interactions, helping you make more informed decisions.
- Webpage Element Analysis: This analyzes the performance and effectiveness of elements like forms, call-to-actions, and links on your web page. It helps you identify which elements are working well and which need improvement.
Reporting Features
- Heat Maps: Heat maps aggregate and visualize webpage clicks, scrolls, and movement data into color-coordinated data points. This visual representation shows where users are engaging most with your site.
- Session Replays: This feature records web visitor sessions, allowing you to watch how users interact with your site in real-time. It provides valuable insights into user behavior and potential pain points.
- Monitoring: Crazy Egg tracks and monitors web visitor behavior continuously, giving you real-time data on how users are interacting with your site.
- Data Segmentation: This feature segments collected data based on predetermined criteria, such as device type, location, or other user attributes. It helps you target specific user groups and optimize their experiences.
User Behavior Features
- Click Tracking: This tracks where users are clicking on a web page, providing detailed information on user interactions with different elements.
- Eye Tracking: Although not a traditional eye-tracking tool, Crazy Egg’s mouse movement and click tracking can give insights into where users are focusing their attention on the page.
- Mouse Movement: This feature tracks mouse movement over a web page, helping you see how users are navigating and interacting with your site.
- Frustration Tracking: This identifies areas where users experience the most difficulty, such as high bounce rates or frequent clicks on non-clickable elements.
A/B Testing Features
- Data Analysis: Crazy Egg offers insights into the relationships between user information and user behavior, which is crucial for A/B testing. It helps you analyze the performance of different versions of your site and identify which variants work best.
- Split URL Testing: This feature allows you to split web traffic to a page between two different URLs, helping you compare the performance of different versions of your site.
Visitor Information Features
- User Identification: This collects user information such as location, IP address, and email, providing a more detailed profile of your visitors.
- Search Box: You can search sessions by keywords or IP address, making it easier to find specific user interactions and analyze them.
Integration with AI
While Crazy Egg itself does not inherently integrate AI for its core features, it can be integrated with AI-driven tools through platforms like Zapier. For example, you can connect Crazy Egg with ChatGPT to automate tasks such as analyzing image content or summarizing data using AI models like OpenAI and Anthropic. This integration can help in extracting, summarizing, and transforming your data more efficiently.
Conclusion
In summary, Crazy Egg provides a comprehensive suite of tools to analyze user behavior, optimize web pages, and improve conversion rates. Its features are designed to give you detailed insights into how users interact with your site, helping you make data-driven decisions to enhance user experience.
Crazy Egg - Performance and Accuracy
Performance of Crazy Egg
Crazy Egg is highly regarded for its performance in the website analytics and optimization category. Here are some key points:Heatmaps and Accuracy
Crazy Egg’s heatmaps are praised for their accuracy, providing clear visualizations of where users click and scroll on a webpage. This helps in identifying areas of high engagement and friction, making it easier to optimize website design and content.A/B Testing
The platform offers robust A/B testing capabilities, allowing users to compare different versions of their website or specific elements to determine which performs better. This feature is highly effective in optimizing user engagement and conversion rates.Session Recordings
Crazy Egg’s session recordings provide valuable insights by capturing and replaying user sessions. This feature helps in understanding how users interact with the website, identifying difficulties, and finding areas for improvement.Engagement
Crazy Egg is effective in enhancing user engagement through several features:User Experience Enhancement
By analyzing click heatmaps, scroll depth, and mouse movement, users can optimize the layout, navigation, and content placement to improve the overall user experience. This leads to increased engagement, lower bounce rates, and improved satisfaction.Conversion Rate Optimization
The platform helps in tracking conversion funnels and analyzing user behavior to identify and address obstacles in the conversion process. This can involve strategic changes to calls-to-action, form layouts, or messaging to improve conversion rates.Limitations and Areas for Improvement
While Crazy Egg is a powerful tool, it has some limitations:Interpretation of Data
Crazy Egg provides data but does not offer explicit recommendations on what changes to make. Users need to interpret the data themselves and may require additional research or usability testing to fully understand the reasons behind user behavior.Limited Screen Recordings
Some users have noted that the number of screen recordings can be limited, and sometimes the recordings can be as short as one second, which may not be very useful.Data Overload
Although Crazy Egg’s features are comprehensive, some users might find the data overwhelming. The platform’s approach of providing fewer but more meaningful features can sometimes be seen as a limitation by those who prefer a broader range of tools.Factual Accuracy
Crazy Egg is known for its factual accuracy in providing insights into user behavior:Correlation with User Behavior
Research from Carnegie Mellon University indicates an 88% correlation between eye movement on a page and subsequent mouse movement in that zone, validating the accuracy of Crazy Egg’s heatmaps and other tracking tools.Detailed Reports and Visualizations
The platform generates detailed reports and visualizations, making it easy to interpret and present the insights gathered. This ensures that the data provided is accurate and actionable. In summary, Crazy Egg performs well in providing accurate and actionable insights into user behavior, but it may require additional interpretation and research to fully leverage its data. Its limitations include the need for users to draw their own conclusions from the data and potential issues with screen recording lengths. Crazy Egg - Pricing and Plans
Plans and Pricing
Basic Plan
This plan is priced at $29/month and is suitable for websites with up to 30,000 monthly pageviews.
Standard Plan
This plan costs $49/month and supports websites with up to 75,000 monthly pageviews.
Plus Plan
Priced at $99/month, this plan is for websites with up to 150,000 monthly pageviews.
Pro Plan
The most comprehensive plan, priced at $249/month, is designed for websites with up to 500,000 monthly pageviews.
Features Across Plans
All plans include key features such as:
- Session Recordings: Allow you to watch how users interact with your site.
- Heatmaps: Include confetti heatmaps to visualize user clicks and interactions.
- A/B Testing: Help you optimize your website by comparing different versions.
- Surveys: Enable you to gather feedback directly from your users.
- Unlimited Team Members and Domains: Available across all plans, making it convenient for teams and multiple websites.
Billing and Trials
- Crazy Egg does not offer a free forever plan. Instead, each plan comes with a 30-day free trial to test the features before committing.
- All plans are billed annually; there is no option for monthly billing.
In summary, Crazy Egg’s pricing is based on the number of monthly pageviews, and while there are no free plans, the 30-day free trial allows you to test the features extensively before choosing a plan.
Crazy Egg - Integration and Compatibility
Integrations
Crazy Egg can be integrated with a variety of tools and platforms to enhance its functionality:
Website Builders and CMSs
It integrates with website builders like Wix, WordPress, and Magento, as well as Google Tag Manager and Segment.
Marketing and UX Tools
Crazy Egg has built-in integrations with tools such as HubSpot, Optimizely, and Shopify. You can also use a simple script to add Crazy Egg to any app that accepts third-party scripts.
Analytics Tools
One of the key integrations is with Google Analytics 4, which can be set up using Zapier. This integration allows you to create new Google Analytics 4 measurements from Crazy Egg data, generate reports when new conversions occur, and track user interactions directly into Google Analytics 4.
Custom Integrations
For tools that are not natively supported, you can use Zapier to create custom integrations. Zapier enables you to connect Crazy Egg with other applications without needing any coding. For example, you can set up triggers in Google Analytics 4 that activate actions in Crazy Egg, such as starting or stopping a snapshot recording based on specific events.
Platform Compatibility
Crazy Egg is compatible with various platforms and devices:
Web Platforms
It works seamlessly with different website builders and CMSs, as mentioned earlier.
Devices and Browsers
Crazy Egg provides insights into how users interact with your site across different devices and browsers. The tool generates heatmaps, scrollmaps, and click reports that show user behavior on various devices.
User Experience and Team Collaboration
Crazy Egg also supports team collaboration and user experience analysis:
Heatmaps and Recordings
These tools help in analyzing user interactions visually, which can be discussed and acted upon by teams directly within the platform.
Surveys and Feedback
You can ask targeted questions to your website visitors and get real-time feedback, which can be integrated into your overall analytics.
In summary, Crazy Egg offers a range of integration options, both native and through third-party services like Zapier, making it compatible with various tools and platforms. Its visual analytics and user interaction tracking features provide valuable insights that complement other analytics tools like Google Analytics.
Crazy Egg - Customer Support and Resources
Customer Support Options
- For immediate assistance, you can contact Crazy Egg’s customer service via their phone number: (714) 398-8373.
- Users can also reach out through email for customer service, legal inquiries, and privacy concerns.
- The company has a dedicated help center on their website, which provides answers to frequently asked questions and guides on how to use their tools effectively.
Additional Resources
- FAQ Section: Crazy Egg has a comprehensive FAQ page that addresses common questions about their services, including how to get started, integration with other platforms, and billing information.
- Guided Tours and Tutorials: Users can take guided tours to learn how to run and analyze snapshot reports, A/B tests, and other features of the platform.
- Integrations: Crazy Egg integrates with various popular services such as Google Analytics, Google Tag Manager, Drupal, Joomla, Magento, Squarespace, WordPress, and more. This allows users to combine Crazy Egg’s visual data with quantitative data from other analytics tools.
- Free Trial and Support During Trial: Users can start with a 30-day free trial, and they can cancel or upgrade to a paid plan at any time. Support is available during the trial period to help users get the most out of the tool.
- Heatmaps, Snapshots, and Recordings: Crazy Egg provides visual reports such as heatmaps, snapshots, and session recordings to help users see how visitors interact with their website. These tools help identify areas where visitors are getting stuck and where improvements can be made.
- Feedback and Surveys: The platform allows users to collect direct feedback from customers through surveys and measure customer experience with NPS scores and ratings.
Community and Documentation
- While there isn’t a specific community forum mentioned, the help center and FAQ sections are well-documented and provide detailed information on using the platform.
- The website also offers tips on how to improve website performance, increase engagement, and optimize conversion rates based on the data provided by Crazy Egg’s tools.
By leveraging these resources, users can effectively use Crazy Egg to optimize their website, improve user experience, and increase conversion rates.
Crazy Egg - Pros and Cons
Pros of Crazy Egg
User-Friendly Setup and Interface
Crazy Egg is incredibly easy to use and does not require any coding skills to set up. It can be installed in minutes as a simple plugin, making it accessible to a wide range of users.
Visual Analytics and Heatmaps
The platform provides detailed visual heatmaps that show where users click, scroll, and hover on your website. This includes click heatmaps, scroll heatmaps, and mouse movement heatmaps, which help in identifying popular and neglected areas of your site.
User Behavior Analysis
Crazy Egg allows for detailed analysis of user behavior, including tracking user clicks, scroll depth, and mouse movement. This helps in identifying areas that need improvement and implementing changes to enhance the user experience.
Session Recordings
The tool offers session recordings that allow you to watch video replays of individual user sessions. This provides valuable insights into how visitors navigate your website, where they encounter difficulties, and where they find value.
A/B Testing
Crazy Egg offers A/B testing capabilities, enabling you to compare different versions of your website or specific elements to determine which design or content changes lead to better user engagement and conversion rates.
Integration with Other Tools
Crazy Egg integrates with other analytics tools like Google Analytics, allowing users to combine visual data with quantitative data for more comprehensive insights into website performance and user behavior.
Conversion Rate Optimization
The platform helps in understanding user actions leading to conversions and those causing drop-offs. By analyzing conversion funnels and user behavior, you can identify and address obstacles in the conversion process.
Cons of Crazy Egg
Pricing
While Crazy Egg offers various pricing plans starting from $49 per month, some users find the pricing to be on the higher side, especially for the advanced features and larger-scale usage.
Limited In-Depth Analysis
Crazy Egg provides data but does not offer a precise explanation of individual users’ actions. It also does not give direct answers on what changes to make, requiring users to interpret the data themselves.
No Support for Native Mobile Apps
Crazy Egg does not support native mobile app frameworks, although it does support mobile websites and progressive web applications (PWAs).
Limited Screen Recordings
Some users have reported that the number of screen recordings is limited, and sometimes the recordings can be as short as one second, which can be useless for detailed analysis.
Confusing Data
Occasionally, the data provided by Crazy Egg can seem confusing, which might require additional time and effort to interpret accurately.
Overall, Crazy Egg is a powerful tool for website optimization, offering valuable insights through heatmaps, session recordings, and A/B testing. However, it has some limitations, particularly in terms of pricing, support for native mobile apps, and the depth of analysis provided.
Crazy Egg - Comparison with Competitors
When Comparing Crazy Egg with Competitors
Unique Features of Crazy Egg
- Heat Maps and Visual Analytics: Crazy Egg is renowned for its heat maps, which include click heatmaps, scroll heatmaps, and mouse movement heatmaps. These tools help visualize user activity on your website, making it easier to identify areas of high engagement and areas that need improvement.
- Session Replays: Crazy Egg offers session replays that record web visitor sessions, allowing you to see exactly how users interact with your site. This feature is invaluable for identifying pain points and areas where users get stuck.
- A/B Testing: The platform provides A/B testing capabilities, enabling you to compare different versions of your web pages to determine which design or content changes drive better results.
- Data Segmentation: Crazy Egg allows you to segment collected data based on predetermined criteria, which helps in analyzing specific user groups and their behaviors.
- Integration with Google Analytics: Crazy Egg integrates with Google Analytics, combining visual data from Crazy Egg with quantitative data from Google Analytics for a more comprehensive view of website performance and user behavior.
Potential Alternatives
Optimizely
- Optimizely is more suited for large-scale A/B testing and personalization. It offers advanced features for experimentation and is often preferred by larger enterprises. While it is more robust, it may be less user-friendly for smaller businesses compared to Crazy Egg.
Hotjar
- Although not explicitly mentioned in the sources, Hotjar is another popular alternative that offers similar features like heat maps, session recordings, and user feedback tools. It is known for its ease of use and comprehensive analytics.
Mouseflow
- Mouseflow is another competitor that provides session replays, heat maps, and funnels to analyze user behavior. It is known for its ability to track user interactions in detail and offer insights into user frustration points.
FullStory
- FullStory offers advanced session replay and analytics tools, focusing on providing a detailed view of user interactions. It is known for its ability to capture every user interaction, making it a strong alternative for those needing deep insights into user behavior.
Key Differences
- User-Friendliness: Crazy Egg is often favored by smaller businesses and those new to website optimization due to its user-friendly interface and focus on heat maps and visual analytics. In contrast, tools like Optimizely are more complex and better suited for larger enterprises.
- Feature Set: While Crazy Egg excels in heat maps and session replays, other tools might offer additional features such as more advanced A/B testing, user feedback tools, or deeper analytics capabilities.
- Pricing: Crazy Egg is noted for its high pricing, which might be a deterrent for some users. Other tools may offer more competitive pricing plans, especially for smaller businesses or startups.
Conclusion
In summary, Crazy Egg stands out with its strong focus on visual analytics, heat maps, and session replays, making it a great choice for businesses looking to improve their website’s user experience and conversion rates. However, depending on your specific needs, alternatives like Optimizely, Hotjar, Mouseflow, or FullStory might offer features that better align with your requirements.
Crazy Egg - Frequently Asked Questions
Frequently Asked Questions about Crazy Egg
What are the main features of Crazy Egg?
Crazy Egg offers a variety of features to help you analyze and improve your website’s performance. Key features include heat maps, session replays, click tracking, eye tracking, and mouse movement tracking. It also provides tools for conversion opportunities analysis, side-by-side analysis, mobile device analysis, and webpage element analysis. Additionally, Crazy Egg supports A/B testing, data segmentation, and integration with other analytics tools like Google Analytics.How does Crazy Egg track user behavior?
Crazy Egg tracks user behavior through several methods, including click tracking, eye tracking, and mouse movement tracking. It generates heat maps to visualize where users click, scroll, and move their mouse on your web pages. This helps you identify which areas of your website are most engaging and where users might be encountering issues.What types of heat maps does Crazy Egg provide?
Crazy Egg provides several types of heat maps, including click heat maps, scroll heat maps, and mouse movement heat maps. These heat maps help you see where users are clicking the most, how far they scroll on a page, and where they hover their mouse. This data is crucial for optimizing your website’s design and layout.Does Crazy Egg support A/B testing?
Yes, Crazy Egg supports A/B testing. This feature allows you to compare different versions of your web pages to see which one performs better in terms of user engagement and conversions. You can use the data from these tests to make informed decisions about your website’s design and content.What are the pricing plans for Crazy Egg?
Crazy Egg offers several pricing plans. The Starter plan is $29/month (billed annually) for up to 5,000 tracked pageviews. The Plus plan is $99/month (billed annually) for up to 150,000 tracked pageviews. The Pro plan is $249/month (billed annually) for up to 500,000 tracked pageviews, and the Enterprise plan is $499/month (billed annually) for up to 1,000,000 tracked pageviews. All plans include a 30-day free trial.Does Crazy Egg offer a free version?
No, Crazy Egg does not offer a free version. However, all plans come with a 30-day free trial, allowing you to test the features before committing to a paid plan.Can Crazy Egg be used on mobile apps?
No, Crazy Egg is designed for website analytics and does not support mobile apps. It is used to track and analyze user behavior on web pages.How does Crazy Egg integrate with other analytics tools?
Crazy Egg integrates seamlessly with other analytics platforms, such as Google Analytics. This integration allows you to combine Crazy Egg’s visual data with the quantitative data from Google Analytics, providing a more comprehensive view of your website’s performance and user behavior.What kind of reporting does Crazy Egg provide?
Crazy Egg provides comprehensive reporting capabilities, including heat maps, session replays, and data segmentation. It generates detailed reports and visualizations that help you interpret and present the insights you gather about user behavior on your website.How do I set up Crazy Egg on my website?
To set up Crazy Egg, you need to add a code snippet to your website. Once the code is in place, the software begins to track individual landing pages and user interactions, providing you with detailed insights into how customers engage with your web pages.Can Crazy Egg help with conversion rate optimization?
Yes, Crazy Egg is very useful for conversion rate optimization. It helps you track and analyze conversions on your website, identify bottlenecks in the conversion process, and make targeted improvements to increase overall conversion rates. You can use features like heat maps, session recordings, and A/B testing to optimize calls-to-action, form layouts, and other elements that impact conversions. Crazy Egg - Conclusion and Recommendation
Final Assessment of Crazy Egg
Crazy Egg is a versatile and user-friendly website analytics tool that offers a range of features to help businesses optimize their website performance and user experience.Key Features
- Heat Maps and Session Replays: Visualize where users click, move, and interact with your website, including dead click maps that show when users click on non-interactive elements.
- User Behavior Tracking: Includes click tracking, eye tracking, mouse movement, and frustration tracking to identify areas where users encounter issues.
- A/B Testing: Allows you to perform split testing to compare different versions of your web pages and identify which elements improve conversions.
- Data Analysis and Reporting: Provides side-by-side analysis, mobile device analysis, data quantification, and webpage element analysis to give a comprehensive view of user behavior.
- Form Analytics: Analyzes user interactions with forms to identify drop-off points and areas of struggle.
Who Would Benefit Most
Crazy Egg is particularly beneficial for smaller businesses and those new to website optimization. It is user-friendly and focuses on visual analytics, making it easier for those without extensive technical expertise to use. Larger enterprises might find it less suitable if they need more advanced features for large-scale A/B testing and personalization, in which case tools like Optimizely might be more appropriate.Pricing
Crazy Egg offers four plans: Basic ($29/month for up to 30,000 pageviews), Standard ($49/month for up to 75,000 pageviews), Plus ($99/month for up to 150,000 pageviews), and Pro ($249/month for up to 500,000 pageviews). All plans come with a 30-day free trial but are billed annually, with no monthly billing option available.Recommendation
If you are looking for a tool to gain clear insights into how users interact with your website, Crazy Egg is a solid choice. Its heat maps, session replays, and A/B testing features provide valuable data to improve your website’s performance and user experience. However, if budget is a concern or you prefer a free or more flexible pricing plan, you might want to consider alternatives like Hotjar, which offers a free forever plan and more flexible billing options.Overall, Crazy Egg is a reliable tool for businesses aiming to enhance their website’s usability and conversion rates, especially for those who value ease of use and clear, visual data analysis.